Additives for orientation control of block copolymers

ABSTRACT

A film layer comprising a high-chi (χ) block copolymer for self-assembly and a surface active polymer (SAP) was prepared on a substrate surface that was neutral wetting to the domains of the self-assembled block copolymer. The block copolymer comprises at least one polycarbonate block and at least one other block (e.g., a styrene-based block). The SAP comprises a hydrophobic fluorinated first repeat unit and a non-fluorinated second repeat unit bearing at least one pendent OH group present as an alcohol or acid (e.g., carboxylic acid). The film layer, whose top surface has contact with an atmosphere, self-assembles to form a lamellar or cylindrical domain pattern having perpendicular orientation with respect to the underlying surface. Other morphologies (e.g., islands and holes of height 1.0Lo) were obtained with films lacking the SAP. The SAP is preferentially miscible with, and lowers the surface energy of, the domain comprising the polycarbonate block.

BACKGROUND

The present invention relates to additives for orientation control ofblock copolymers used in directed self-assembly applications, and morespecifically to random copolymer additives comprising non-fluorinatedhydrogen-bond donating repeat units and fluorinated non-hydrogen-bonddonating repeat units for top orientation-control of high-chi (χ) blockcopolymers containing a polycarbonate block.

Block copolymers (BCPs) find many applications in solution, bulk andthin films. Thin film applications of BCPs are particularly attractivefor nanolithography and patterning due to the ability of some BCPs toform periodic self-assembled structures ranging in feature size from 5nm to 50 nm. The thin-film self-assembly property of BCPs can beutilized with existing photolithographic techniques to provide a uniqueapproach to long range order for semiconductor applications. Thisapproach, called directed self-assembly (DSA) of block copolymers,promises to extend the patterning capabilities of conventionallithography.

BCPs for directed self-assembly (DSA) applications comprise two or threepolymer blocks that can phase separate into domains characterized byordered nanoscopic arrays of spheres, cylinders, gyroids, and lamellae.The ability of a BCP to phase separate depends on the Flory Hugginsinteraction parameter chi (χ). Poly(styrene)-block-poly(methylmethacrylate), abbreviated as PS-b-PMMA, is the most widely used blockcopolymer for DSA. For PS-b-PMMA, the poly(styrene) block (PS) and thepoly(methyl methacrylate) block (PMMA) have similar surface energies atthe polymer-air interface. In this instance, annealing a thin layer ofthe BCP, which is disposed on an orientation control layer, inducesphase separation to produce BCP domains that are perpendicularlyoriented to the orientation control layer. Typically, for PS-b-PMMA theorientation control layer is a crosslinkable or brush-type randomcopolymer formed with styrene and methyl methacrylate. The neutralwetting properties of the orientation control layer (underlayer) can becontrolled by adjusting the composition of styrene and methylmethacrylate in order to enable perpendicular orientation of the BCPlamellar domains.

The minimum half-pitch of PS-b-PMMA is limited to about 10 nm because ofthe lower interaction and interaction parameter chi (χ) between PS andPMMA. To enable further feature miniaturization, a block copolymerhaving a high interaction parameter between two blocks (high chi blockcopolymer) is desirable. Several block copolymers having higherinteraction parameters between the two blocks have been studied toobtain smaller feature sizes. Of particular interest are blockcopolymers comprising a block derived from ring opening of a cycliccarbonyl monomer from a reactive end-group on the first polymer block.Block copolymers formed by ring opening polymerization (ROP) of cyclicmonomers (e.g., lactides, lactones, ethylene oxide) have been used togenerate sub-10 nm feature sizes for patterning applications.

As the interaction parameter between the two blocks of the blockcopolymer increases, neutral underlayer properties alone may not besufficient for forming perpendicularly oriented block copolymer domainsdue to the increased mismatch between the polymer-air surface energiesof the two blocks. This causes parallel orientation of the blockcopolymer domains with only the lower surface energy block present atthe polymer-air interface, rendering the thin-film undesirable forlithographic applications. Top-coat based orientation control strategieshave been employed to control the surface energy at the polymer-airinterface of the blocks. However, these strategies introduce additionalprocess complexity in the integration of high-chi block copolymers intostandard lithography processes.

There exists a need to develop a top-coat free method forperpendicularly orienting block copolymer domains of a high-chi blockcopolymer with sub-10 nm half-pitch.

SUMMARY

A composition is disclosed, comprising:

i) a solvent;

ii) a block copolymer comprising:

-   -   a) a first block comprising a repeat unit of formula (B-1):

wherein I) R^(w) is a monovalent radical selected from the groupconsisting of H, methyl, ethyl, and trifluoromethyl (*—CF₃) and II)R^(d) is a monovalent radical comprising an aromatic ring linked tocarbon 1, and

-   -   b) an aliphatic polycarbonate second block (polycarbonate block)        linked to the first block; and

iii) a surface active polymer (SAP), comprising:

-   -   about 40 mol % to about 90 mol %, based on total moles of        monomers used to prepare the SAP, of a fluorinated repeat unit        (first repeat unit), wherein the first repeat unit has a        chemical structure having no functionality capable of donating a        hydrogen to form a hydrogen bond,    -   about 10 mol % to about 60 mol %, based on total moles of        monomers used to prepare the SAP, of a non-fluorinated second        repeat unit comprising a functional group selected from the        group consisting of alcohols, carboxylic acids, phosphonic        acids, and sulfonic acids;        wherein    -   the block copolymer and the SAP are dissolved in the solvent.

Also disclosed is a method, comprising:

providing a first layered structure comprising a top layer (underlayer);

disposing the composition of claim 1 on the underlayer and removing anysolvent, thereby forming a second layered structure comprising a filmlayer disposed on the underlayer, wherein the film layer comprises theblock copolymer and the SAP in non-covalent association, and the filmlayer has a top surface in contact with an atmosphere; and

allowing or inducing the block copolymer of the film layer toself-assemble, thereby forming a third layered structure comprising aphase separated domain pattern having a characteristic pitch Lo, thedomain pattern comprising alternating domains comprising respectivechemically distinct blocks of the block copolymer;

wherein

each of the domains has contact with the underlayer and the atmosphere,and

a domain comprising the polycarbonate block has a higher concentrationof the SAP compared to a domain comprising the first block of the blockcopolymer.

Another method is disclosed, comprising:

providing a first layered structure comprising a top layer (underlayer);

forming a topographical resist pattern disposed on the underlayer, theresist pattern comprising features having recessed regions, the recessedregions having a bottom surface which is a portion of a surface of theunderlayer;

disposing the composition of claim 1 substantially in the recessedregions of the resist pattern and removing any solvent, thereby forminga second layered structure comprising a film layer, the film layercomprising the block copolymer and the SAP, wherein the film layer is incontact with the bottom surface, the bottom surface is neutral wettingto the block copolymer, and the film layer has a top surface in contactwith an atmosphere; and

allowing or inducing the block copolymer to self-assemble, therebyforming a third layered structure comprising a pattern of phaseseparated domains (domain pattern) of the block copolymer in therecessed regions, wherein each of the domains is in contact with thebottom surface and the atmosphere, and each of domains is orientedperpendicular to a main plane of the underlayer.

Also disclosed is a surface active polymer (SAP) of formula (H-5):E′-P′-E″  (H-5),wherein

E′ is a first end group,

E″ is a second end group, and

P′ is a polymer chain consisting essentially of:

-   -   i) first repeat units selected from the group consisting of:

and combinations thereof, wherein each R′ is independently selected fromthe group consisting of hydrogen (*—H), methyl (*-Me), ethyl (*-Et), andtrifluormethyl (*—CF₃), and each n′ is an independent integer having avalue of 1 to 12, and

-   -   ii) second repeat units selected from the group consisting of

and combinations thereof, wherein each R″ is independently selected fromthe group consisting of *—H, *-Me, *-Et.

The above-described and other features and advantages of the presentinvention will be appreciated and understood by those skilled in the artfrom the following detailed description, drawings, and appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIGS. 1A to 1F are cross-sectional layer diagrams showing a process offorming a perpendicularly oriented lamellar domain pattern using aself-assembly layer (SA layer) comprising a disclosed high-chi blockcopolymer comprising a polycarbonate block and a disclosed surfaceactive polymer (SAP). The underlayer is neutral wetting to the blockcopolymer.

FIGS. 2A to 2E are cross-sectional layer diagrams showing a process offorming a perpendicularly oriented lamellar domain pattern in thepresence of a topographic pre-pattern. The air interface is not neutralwetting to the block copolymer in the absence of the SAP. The airinterface becomes neutral wetting to the block copolymer duringself-assembly. The resist features can be non-neutral wetting to the SAlayer comprising the high-chi block copolymer and SAP.

FIG. 3 is an AFM height image of the self-assembled block copolymer filmof Example 66.

FIG. 4 is an AFM height image of the self-assembled block copolymer filmof Example 67.

FIG. 5 is an AFM height image of the self-assembled block copolymer filmof Example 68.

FIG. 6 is an AFM height image of the self-assembled block copolymer filmof Example 69.

FIG. 7 is an AFM height image of the self-assembled block copolymer filmof Example 70.

FIG. 8 is an AFM height image of the self-assembled block copolymer filmof Example 71.

FIG. 9 is an AFM height image of the self-assembled block copolymer filmof Example 72.

FIG. 10 is an AFM height image of the self-assembled block copolymerfilm of Example 73.

FIG. 11 is an AFM height image of the self-assembled block copolymerfilm of Example 74.

FIG. 12 is an AFM height image of the self-assembled block copolymerfilm of Example 75.

FIG. 13 is an AFM height image of the self-assembled block copolymerfilm of Example 76.

FIG. 14 is an AFM height image of the self-assembled block copolymerfilm of Example 77.

FIG. 15 is an AFM height image of the self-assembled block copolymerfilm of Example 78.

FIG. 16 is a set of AFM height images at two magnifications of theself-assembled block copolymer film of Example 79.

FIG. 17 is an AFM height image of the self-assembled block copolymerfilm of Example 83.

FIG. 18 is an AFM height image of the self-assembled block copolymerfilm of Example 84.

FIG. 19 is an AFM height image of the self-assembled block copolymerfilm of Example 85.

FIG. 20 is an AFM height image of the self-assembled block copolymerfilm of Example 86.

FIG. 21 is an AFM height image of the self-assembled block copolymerfilm of Example 87.

FIG. 22 is an AFM height image of the self-assembled block copolymerfilm of Example 88.

FIG. 23 is an AFM height image of the self-assembled block copolymerfilm of Example 89.

FIG. 24 is an AFM height image of the self-assembled block copolymerfilm of Example 90.

FIG. 25 is an AFM height image of the self-assembled block copolymerfilm of Example 91.

FIG. 26 is an AFM height image of the self-assembled block copolymerfilm of Example 92.

FIG. 27 is an AFM height image of the self-assembled block copolymerfilm of Example 93.

FIG. 28 is an AFM height image of the self-assembled block copolymerfilm of Example 94.

FIG. 29 is an AFM height image of the self-assembled block copolymerfilm of Example 95.

FIG. 30 is a schematic cross-sectional representation (Scheme 1) ofparallel oriented lamellar domains of a self-assembled diblockcopolymer. The main plane of each lamellar domain is parallel to theplane of the underlayer surface.

FIG. 31 is a schematic cross-sectional representation (Scheme 2) ofparallel oriented lamellar domains of a self-assembled BCP when theatmosphere is non-neutral to the BCP, and the self-assembly processforms islands and holes on a neutral underlayer surface.

FIG. 32 is a schematic cross-sectional representation (Scheme 3) ofperpendicularly oriented lamellar domains of a self-assembled BCP inwhich the SA layer comprises an SAP that is preferentially soluble inthe domain comprising block B.

DETAILED DESCRIPTION

Disclosed are phase-selective and surface active polymers (SAPs) forlithographic processes utilizing self-assembly of block copolymers. TheSAPs are also referred to below as “polymer additives”. The SAPs provideorientation control of phase domains formed by self-assembly of high-chiblock copolymers (BCPs) comprising a polycarbonate block. “High-chi”means the BCPs have a large Flory-Huggins interaction parameter chi (χ).The higher the chi parameter, the poorer the miscibility of thedifferent BCP blocks with one another, and the sharper the phaseboundaries separating the phase domains containing the different blocksafter self-assembly of the BCP. The SAPs are preferentially soluble inthe polycarbonate domain formed by self-assembly (i.e., the domaincomprising the polycarbonate block of the block copolymer). The SAPsalso lower the surface energy of the polycarbonate domain compared to anotherwise identical polycarbonate domain lacking the SAP, therebyallowing the polycarbonate domain to wet the atmosphere interfaceresulting in lamellae and cylinders having a perpendicular orientationwith respect to the main plane of the substrate.

Herein, an “atmosphere” is a gas, which can include air and/or one ormore other gases at any suitable pressure in contact with the topsurface of the SA layer.

Herein, “non-fluorinated” means the chemical formula of a referencedmaterial contains no fluorine. The referenced material can be asub-structure of a polymer such as a repeat unit. A material is“fluorinated” if the chemical formula of the material contains one ormore fluorines. A material described as containing one or more“fluorines”, “fluorine groups”, or “fluoride groups” herein means thematerial has a chemical structure in which one or more monovalentfluorine atoms are covalently bound to carbon(s) of the chemicalstructure.

An “SA material” is a material capable of self-assembling intocompositionally different phase-separated domains. Self-assembly (SA)refers to a process in which the SA material undergoes phase separationto produce a pattern of immiscible solid phase domains under suitableconditions. Self-assembly can occur spontaneously upon formation of theSA layer, or self-assembly can be induced (e.g., by annealing an SAlayer comprising an SA material at an elevated temperature for asuitable period of time). The SA material is preferably a blockcopolymer (BCP).

A block copolymer for self-assembly comprises at least two blocks thatare immiscible with each other. Non-limiting block copolymers includediblock and triblock copolymers. Self-assembly of the block copolymeroccurs by phase separation of the blocks to form a pattern of segregatedsolid phase domains. Depending on the volume fraction of the blocks, thedomains can have the form of lamellae, spheres, cylinders, and/orgyroids. As an example, self-assembly of a diblock copolymer can producea domain pattern comprising a first lamellar domain containingsubstantially a first block A of the diblock copolymer and a secondlamellar domain containing substantially a second block B of the diblockcopolymer. In this instance, the first and second lamellar domains arelinked by the covalent bond joining block A to block B of the blockcopolymer.

Herein, an “SA layer” is a layer comprising an SA material and an SAP.The SA layer is disposed on a top surface of a substrate. The SA layercan comprise other materials.

Herein, any material of the top surface of the substrate that hascontact with the bottom of the SA layer is referred to generally as“underlayer material” or “orientation control material”. A layercomprising underlayer material is an “underlayer” or “orientationcontrol layer”. The underlayer surface influences self-assembly of an SAmaterial of the SA layer.

A surface is said to have a “preferential affinity for” or is“preferential to” a referenced domain of a self-assembled SA material ifthe referenced domain can wet the surface in preference to anotherdomain of the self-assembled SA material. Otherwise, the surface is saidto be “non-preferential” to the referenced domain.

The substrate is the layered structure on which the SA layer isdisposed. The substrate has a main plane, which is parallel to thebottom-most layer of the substrate. The substrate can comprise one ormore layers of materials arranged in a stack, more specificallymaterials used in the fabrication of semiconductor devices. Asnon-limiting examples, the substrate can include a bottom layer (e.g.,silicon wafer, metal foil), hard mask layer, dielectric layer, metaloxide layer, silicon oxide layer, silicon nitride, titanium nitride,hafnium oxide, an anti-reflection layer (ARC), and/or an orientationcontrol layer (underlayer) for self-assembly. The SA layer is disposedon the top surface of the substrate, which is typically the top surfaceof the orientation control layer. When a resist pattern is formed on theorientation control layer, the substrate includes the resist pattern. Inthis instance, the SA layer can be disposed in the trenches of theresist pattern.

The top surface of the substrate can be a “graphoepitaxial pre-pattern”or a “chemical pre-pattern” for self-assembly. Each type of pre-patterncan be composed of topographical features, such as in a resist pattern.A graphoepitaxial pre-pattern influences self-assembly by the topographyand surface properties of the pre-pattern. A “chemical pre-pattern”influences self-assembly predominantly by way of the surface propertiesof different regions of the pre-pattern. No sharp dimensional limitsexist between these two pre-pattern categories because the extent oftopographical influence on self-assembly is also dependent on thethickness of the SA layer in relation to the underlying relief surface,as well as the annealing conditions (time and temperature) used forself-assembly. In general, however, when graphoepitaxial pre-patternsare used, the thickness of the SA layer is less than or equal to theheight of the topographical features of the pre-pattern. For chemicalpre-patterns, the SA layer thickness is greater than any height of theunderlying topographical features of the pre-pattern.

The term “interface” refers to a contact boundary between twosubstantially immiscible phases. Each phase can, independently, be asolid, a liquid, or a gas.

A lamellar or cylindrical domain can be oriented parallel orperpendicular to the plane of the underlying orientation control layer(underlayer) or the main plane of the SA layer. A lamellar domain has aparallel orientation when the main plane or plate of the lamellar domainis oriented parallel to the main plane of the underlying surface (or SAlayer). A lamellar domain has a perpendicular orientation when the mainplane or plate of the lamellar domain is oriented perpendicular to themain plane of the underlying surface (or SA layer). A cylindrical domainhas a parallel orientation when the cylinder axis is oriented parallelto the main plane of the underlying surface (or SA layer). A cylindricaldomain has a perpendicular orientation when the cylinder axis isoriented perpendicular to the main plane of the underlying surface (orSA layer).

Domain orientation can also be expressed relative to the main plane ofthe substrate. A lamellar domain has a parallel orientation when themain plane or plate of the lamellar domain is oriented parallel to themain plane of the substrate. A lamellar domain has a perpendicularorientation when the main plane or plate of the lamellar domain isoriented perpendicular to the main plane of the substrate. A cylindricaldomain has a parallel orientation when the cylinder axis is orientedparallel to the main plane of the substrate. A cylindrical domain has aperpendicular orientation when the cylinder axis is orientedperpendicular to the main plane of the substrate.

Perpendicular orientation of lamellar domains is desirable for forminghigh resolution line patterns by selective etching of a given lamellardomain. Parallel orientation is not desirable for forming highresolution line patterns.

The term “disposed” refers to a layer in contact with a surface ofanother layer. “Disposing” or “applying” refer to forming a layer to bein contact with a surface of another layer, without limitation as to themethod employed unless otherwise stated, with the proviso that thedesirable characteristics of the disposed or applied layer are obtained,such as uniformity and thickness.

The term “casting” refers to forming a layer of a material by disposingon a surface a solution of the material dissolved in a solvent, andremoving the solvent.

Random copolymers are indicated by “-co-”, or “-r-” in the name. Blockcopolymers are indicated by “-b-” or “-block-” in the name. Alternatingblock copolymers are indicated by “-alt-” in the name.

Herein, “symmetrical wetting” means the underlayer surface and theatmosphere interface are wetted by the same domain(s) of theself-assembled SA material. “Non-symmetrical” wetting means theunderlayer surface and the atmosphere interface are wetted by differentdomain(s) of the self-assembled SA material.

Herein, a surface or an atmosphere interface is said to be “neutral” toan SA material, or “neutral wetting” with respect to an SA material ifeach domain of the self-assembled SA material has contact with thesurface or the atmosphere interface after self-assembly. Otherwise, thesurface or atmosphere interface is said to be “non-neutral” to the SAmaterial. For example, an underlayer surface is “neutral wetting” to ablock copolymer if after self-assembly each domain of the self-assembledblock copolymer has contact with the underlayer surface. It should beunderstood that each domain of the self-assembled SA material cancomprise SAP, and each domain can have a different concentration of SAPafter self-assembly. A neutral underlayer surface allows orientationcontrol but does not guide the lateral spatial arrangement of theself-assembled domains. A non-neutral underlayer surface can guideself-assembly. For purposes of the invention, it is desirable for theunderlayer and the atmosphere to be neutral wetting to the domainsformed by self-assembly of the SA layer comprising the SA material andthe SAP.

For commercial purposes, the underlayer surface and the atmosphereinterface must be non-preferential (neutral) to the SA material in orderto obtain perpendicularly oriented lamellar domains when no otherchemical or topographical features are available to influenceself-assembly of the block copolymer. If only one interface is neutralto the SA material, the lamellar domains orient parallel to theunderlayer surface to form an island/hole morphology having 0.5Lo (“Lnought”) step height. “Step height” refers to height difference relativeto the surrounding SA material and Lo is the characteristic pitch (bulkperiodicity) of the domains of the self-assembled SA material. Thehigher the chi parameter of the SA material, the smaller the potentialLo (pitch) of the domain pattern.

These parameters are illustrated in the diagrams of Schemes 1-3 (FIGS.30-32) described further below. If only the underlayer surface isneutral, both block copolymer (BCP) domains initially wet the underlayersurface with 0.5Lo perpendicular lamellae, but eventually form parallelmorphology as the atmosphere (e.g., air) is non-neutral, resulting inisland/holes with parallel lamellae having 0.5Lo step height.

For purposes of demonstrating the present invention, the substratecomprises an orientation control layer (underlayer) disposed on asilicon wafer. The underlayer surface can be a planar surface havinguniform surface properties (i.e., the underlayer surface has notopographical or chemical patterning). Most of the examples furtherbelow utilize a planar underlayer. Other examples utilize a substratehaving a topographic resist pattern on the underlayer for graphoepitaxy.The SA layer is disposed on the underlayer and has a top surface incontact with an atmosphere. It is desirable that self-assembly of the SAlayer comprising the SA material and the SAP forms a lamellar domainpattern comprising alternating perpendicularly oriented lamellae of eachdomain that are in contact with the underlayer and the atmosphere. Theunderlayer material can be any material having suitable neutral wettingproperties to the domains of the given SA material.

The SA layer has the following characteristics. The SA layer comprises ahigh-chi BCP comprising an aliphatic polycarbonate block. Additionally,the BCP has a structure favoring formation of lamellar domains orcylindrical domains during self-assembly. That is, the volume fractionsof the blocks of the block copolymer are in a range favorable tolamellar domain or cylindrical domain formation. Also, the SA layer isdisposed on the underlayer surface, which is neutral wetting to thedomains of the self-assembled BCP. Lastly, the SA layer has a topsurface in contact with an atmosphere. The atmosphere interface, whichis typically air, is not neutral to the BCP, meaning less than alldomains at the top surface of the self-assembled SA layer are in contactwith the atmosphere when the SA layer consists essentially of BCP. Underthese conditions, typically only one domain of the self-assembled BCPhas contact with the atmosphere (lamellae have a parallel orientation).In general, the higher the chi parameter of the BCP, the greater themismatch in surface properties between the underlayer surface and theatmosphere, causing parallel orientation of lamellar domains.

Given the foregoing characteristics of the SA layer, an SA layer thatcontains no SAP self-assembles to form parallel oriented lamellardomains, due to less than all domains being capable of “wetting” theatmosphere. Parallel oriented lamellar domains are characterized by theappearance of islands and holes in atomic force microscopy (AFM) heightimages (Scheme 2, FIG. 31). It is desirable that self-assembly of the SAlayer comprising the SA material and the SAP forms a lamellar domainpattern wherein each domain is in contact with the underlayer and theatmosphere. The underlayer material can be any material having suitableneutral wetting properties to the domains of the given SA material.

The following discussion is focused on lamellar domain patterns formedby self-assembly of a diblock copolymer, but is applicable to otherblock copolymers (e.g., triblock copolymers) and other domainmorphologies (e.g., cylindrical domains). It should be understood thatthe layer diagrams are not drawn to scale or meant to be limiting withrespect to the possible structures that can be produced using thebelow-described processes. The diagrams are intended for illustrationpurposes.

Without being bound by theory, Scheme 1 (FIG. 30) is a schematiccross-sectional representation of parallel oriented lamellar domains ofa self-assembled diblock copolymer. The main plane of each lamellardomain is parallel to the plane of the underlayer surface.

Scheme 1 shows the arrangement of blocks A and B of a diblock copolymerafter self-assembly of the diblock copolymer on an underlayer surfacethat is preferential to the domain containing block A. In this example,the underlayer and atmosphere interface have preferential affinity tothe domain containing block A. The first lamellar domain comprises blockA and the second lamellar domain comprises block B. The bulk periodicityLo of the domains is indicated by 1.0Lo (1.0 times Lo). The individualdiblock copolymer macromolecules, domain boundaries, and 0.5Lo are alsoindicated. It should be understood that within a given lamellar domain(e.g., the second lamellar domain of Scheme 1) blocks from differentpolymer macromolecules (e.g., B blocks) can be arranged end-to-end(shown) and/or interwoven (not shown). Each block can have a backbonethat is rigid, non-rigid, or of intermediate rigidity. Each block canhave any suitable coiling, rotational and/or flexural capability.

For purposes of the present invention, the atmosphere interface isalways a non-neutral interface with respect to the high-chi BCPs. An SAlayer consisting essentially of a high-chi BCP in contact with theatmosphere interface will almost certainly undergo self-assembly to formislands and holes whose boundaries represent a disruption in paralleloriented lamellae. This occurs regardless of whether the underlayer isneutral or non-neutral to the BCP.

Scheme 2 (FIG. 31) is a schematic cross-sectional representation ofparallel oriented lamellar domains of a self-assembled BCP when theatmosphere is non-neutral to the BCP, and the self-assembly processforms islands and holes on a neutral underlayer surface.

In Scheme 2, the underlayer surface is in contact with the domaincontaining block A and the domain containing block B, and only the blockA domain has contact with the atmosphere. The neutral (non-preferential)wetting properties of the underlayer surface cause disruptions in theparallel oriented lamellar domains, resulting in formation of islandsand holes having a step height h′ by AFM of about 0.5 Lo. It should beunderstood that block A phase separates to retain contact with theatmosphere, including in the disruption zone of the lamellar domains(the boundary of the hole and the island). No attempt has been made tocharacterize the arrangement of blocks B in the disruption zone ofScheme 2.

The examples further below show that an SA layer comprising a BCP and adisclosed SAP can self-assemble to form perpendicularly orientedlamellar domains when the top surface of the SA layer has contact withthe atmosphere. The SAP is preferentially miscible with thepolycarbonate domain (i.e., the domain comprising the polycarbonateblock of the self-assembled BCP) and substantially immiscible withnon-polycarbonate domains of the self-assembled block copolymer (e.g., ablock prepared from a vinyl polymerizable monomer such as styrene and/orsubstituted styrenes).

Without being bound by theory, self-assembly is believed to produce apolycarbonate domain having a greater concentration of SAP than thenon-polycarbonate domain. The higher SAP concentration of thepolycarbonate domain after self-assembly may allow the SAP-enrichedpolycarbonate domain to wet the atmosphere interface, thereby allowingperpendicularly orientation of the lamellar domains. Non-polycarbonatedomains having contact with the atmosphere can be essentially free ofSAP at the atmosphere interface. When the block copolymer structurefavors cylindrical domain formation, the presence of the SAP can allowformation of perpendicularly oriented cylindrical domains.

Scheme 3 (FIG. 32) is a schematic cross-sectional representation ofperpendicularly oriented lamellar domains of a self-assembled BCP inwhich the SA layer comprises a SAP that is preferentially soluble in thedomain comprising block B. The SAP is represented by the forward slashmarks within the block B and block A domains. The block B domain cancomprise a concentration gradient in SAP, wherein the concentration ofSAP is highest at the atmosphere interface (not shown). The block Adomain can have essentially no SAP at the atmosphere interface.

In Scheme 3, the main planes of the lamellae are oriented perpendicularto the plane of the underlayer surface, and also to the main plane ofthe SA layer. The lamellae of each domain are in contact with theatmosphere and underlayer surface. The bulk periodicity, Lo, isindicated, as well as 0.5Lo. In this example, the underlayer surface hascontact with block A and block B of the self-assembled diblockcopolymer. Therefore, the underlayer is neutral to the self-assembleddiblock copolymer. The presence of the SAP allows the SAP-containingblock B domain to contact the atmosphere interface.

The examples further below were carried out using a neutral underlayer.If an SA layer comprising a self-assembled BCP exhibits islands and/orholes or parallel cylinders by atomic force microscopy, the atmosphereinterface (air interface) is non-neutral to the self-assembled SA layer(undesirable). If an SA layer comprising a self-assembled BCP exhibitsperpendicularly oriented lamellae or cylinders, the atmosphere interface(air interface) is neutral to the self-assembled SA layer (desirable).

The examples further below show that the SAP allows perpendicularlyoriented domain patterns to be formed without employing a top coat(i.e., a layer between the SA layer and the atmosphere interface) oremploying a topographic pre-pattern to direct self-assembly of thehigh-chi BCP. Although a topographic pre-pattern is not essential fororientation control, a topographic pre-pattern can be present for otherpurposes. This is also demonstrated in the examples further below.

The lamellar domain patterns can have a bulk periodicity, Lo, in therange of about 4 nm to about 80 nm, which is useful for producing linefeatures having a half-pitch of about 2 nm to about 40 nm, respectively,more particularly about 2 nm to about 20 nm.

Surface Active Polymers (SAPs)

The SAP is phase selective, meaning the SAP has preferential solubilityin the polycarbonate domain formed by self-assembly. As a result, thepolycarbonate domain has a higher concentration of SAP afterself-assembly compared to other domains. The SAP concentration of thepolycarbonate domain after self-assembly lowers the surface energy ofthe polycarbonate domain sufficiently to allow the polycarbonate domainto wet the atmosphere interface and provide perpendicular orientation ofeach domain. Perpendicular orientation can be achieved without forming amonolayer of SAP over the SA layer. For this reason, the SAP can be usedin amounts of more than 0 wt % up to about 10 wt %, more specificallyabout 0.1 wt % to about 10 wt %, and even more specifically 0.1 wt % toabout 5 wt %, based on total weight of the dry solids of the SA layer.In an embodiment, the formulation used to prepare the SA layer comprisesabout 0.5 wt % to about 5 wt % SAP based on total weight of dry solidsof the SA layer. In another embodiment, the formulation used to preparethe SA layer comprises about 1.5 wt % to about 3 wt % SAP based on totalweight of dry solids of the SA layer.

The SAP is preferably a linear random copolymer having preferentialsolubility in the polycarbonate domain. Other polymer architectures(e.g., dendritic polymers, star polymers, and block polymers) are notexcluded as long as the SAP is preferentially soluble in thepolycarbonate domain and does not form a discrete domain duringself-assembly that is separate and distinct from the polycarbonatedomain. A random copolymer is a polymer comprising a random distributionof the different repeat units making up the polymer backbone. Randomcopolymer names can include an “-r-”, “-co-”, or “-random-” separatingthe abbreviated monomer names used to prepare the polymer. Herein, alinear polymer has a one polymer branch having two peripheral ends(i.e., dangling ends, as in a segment of a rope).

The SAP can be prepared by any suitable polymerization technique.Exemplary polymerization techniques include radical polymerization, atomtransfer radical polymerization (ATRP), reversibleaddition-fragmentation chain-transfer polymerization (RAFT), ionicpolymerization, ring opening polymerization, and ring-opening metathesispolymerization (ROMP). Non-limiting monomers for forming an SAP includevinyl polymerizable monomers (e.g., styrenes, acrylates, methacrylates)and cyclic monomers (e.g., cyclic ethers, cyclic carbonates).

The SAP comprises a hydrophobic fluorinated repeat unit (first repeatunit). Preferably, the first repeat unit comprises a side chainfunctional group selected from the group consisting of fluorinatedaromatic rings and fluorinated esters. The first repeat unit can have astructure in accordance with formula (H-1):

wherein

Q′ is a monovalent radical comprising an aromatic ring and/or an estergroup,

R′ is a monovalent radical selected from the group consisting of *—H,methyl (*—CH₃), ethyl (*-Et), and trifluoromethyl (*—CF₃), and

Q′ and/or R′ comprises at least one fluorine.

Herein, a bond with an asterisk is a starred bond. Starred bonds are notmethyl groups. It should be understood that an atomic center shown witha starred bond is linked by a covalent bond to another specified orunspecified atomic center of a chemical structure. A starred bond can besaid to be “linked to” a referenced structure or atomic center, meaningthat the atomic center shown having the starred bond is linked by acovalent bond to the referenced structure or atomic center.

The chemical structure of the first repeat unit has no functionalitycapable of donating a hydrogen to form a hydrogen bond. Non-limitingfunctionality capable of donating a hydrogen to form a hydrogen bondinclude alkyl and aryl alcohols, alkyl and aryl carboxylic acids, alkyland aryl peracids, alkyl and aryl hydrogen peroxides, alkyl and arylsulfonic acids, alkyl and aryl sulfinic acids, alkyl and aryl mono- anddi-esters of phosphoric acid, alkyl and aryl monoesters of phosphonicacids, alkyl and aryl primary amines, alkyl and aryl secondary amines,alkyl and aryl hydroxylamines, alkyl and aryl primary and secondaryamides, and alkyl and aryl primary and secondary sulfonamides. In anembodiment, the first repeat unit has a chemical structure that excludesfunctionality capable of donating a hydrogen to form a hydrogen bond.

More specific first repeat units have a structure in accordance withformula (H-2):

wherein

a′ is an integer having a value of 0-5,

each R^(c) is an independent monovalent radical selected from the groupconsisting of fluoride (*—F), chloride (*—Cl), bromide (*—Br),fluorinated and non-fluorinated alkyl groups comprising 1-3 carbons, andfluorinated and non-fluorinated alkoxy groups comprising 1-3 carbons,

R′ is a monovalent radical selected from the group consisting ofhydrogen (*—H), methyl (*—CH₃), ethyl (*-Et), and trifluoromethyl(*—CF₃), and

the first repeat unit comprises at least one fluorine.

When a starred bond of a given group crosses a bond of a ring as shownin the above structure, the group can be linked to any one of theavailable positional isomers of the ring. The group can be present as amixture of positional isomers. This convention is followed below also.It should be understood that any of aromatic ring centers labelled 2-6of formula (H-2), which are not linked to an R^(c) group, are linked tohydrogen. In a preferred embodiment, R′ is hydrogen, a′ is 5, and eachR^(c) is fluoride. That is, the aromatic ring moiety is apentafluorophenyl group and the first repeat unit is apentafluorophenylethylen-1,2-yl group, which can be formed by vinylpolymerization of pentafluorostyrene:

Other more specific first repeat units have structures in accordancewith formula (H-3):

wherein

R^(d) is a monovalent radical selected from the group consisting offluorinated alkyl groups comprising 1-30 carbons, fluorinated arylgroups comprising 1-30 carbons, and fluorinated poly(alkylene oxide)groups comprising 4 to 30 carbons, and

R′ is a monovalent radical selected from the group consisting of *—H,methyl (*—CH₃), ethyl (*-Et), and trifluoromethyl (*—CF₃).

Exemplary non-limiting fluorinated first repeat units include those ofScheme 4.

Scheme 4.

In an embodiment, the fluorinated first repeat unit is selected from thegroup consisting of

and combinations thereof, wherein each R′ is independently selected fromthe group consisting of hydrogen (*—H), methyl (*-Me), ethyl (*-Et), andtrifluormethyl (*—CF₃), and each n′ is an independent integer having avalue of 1 to 12. In another embodiment, the first repeat unit is

In another embodiment, the first repeat unit is

The SAP further comprises a non-fluorinated second repeat unit, whichcomprises at least one hydroxy group capable of donating a hydrogen toform a hydrogen bond. Each hydroxy group of the second repeat unit canindependently be present as an alcohol, a hydroxy group of a carboxylicacid, a hydroxy group of a phosphonic acid, or a hydroxy group of asulfonic acid group. That is, the second repeat unit can comprise amember of the group consisting of alcohols, carboxylic acids, phosphonicacids, sulfonic acids, and combinations thereof. In an embodiment, thesecond repeat unit comprises a phenol.

More specific second repeat units of the SAP have structures inaccordance with formula (H-4):

Q″ is a single bond or a linking group having a valency of b′+1 andcomprising at least one carbon,

each J″ is an independent monovalent radical selected from the groupconsisting of alcohols, carboxylic acids, phosphonic acids, and sulfonicacids, and

R″ is a monovalent radical selected from the group consisting of *—H,methyl (*—CH₃), ethyl (*-Et).

Preferably, Q″ comprises an aromatic ring, ester carbonyl, or amidecarbonyl group linked to carbon 1 of formula (H-4). In an embodiment,each J″ is selected from the group consisting of *—OH, and *—COOH.

More specific Q″ groups include those of Scheme 5, wherein the starredbond of carbon 1 of Q″ is linked to carbon 1 bearing the R″ group offormula (H-4), and each remaining starred bond of Q″ is linked to a J″group.

More specific second repeat units of the SAP include those of Scheme 6.

In an embodiment, the second repeat unit of the SAP is selected from thegroup consisting of

and combinations thereof, wherein each R″ is independently selected fromthe group consisting of *—H, *-Me, *-Et.

The SAP can comprise the second repeat units singularly or incombination.

Monomers used to form the second repeat units, referred to herein as“second monomers”, can be the corresponding styrene, methacrylate, ormethacrylamide monomers of the above-mentioned first repeat units orprotected forms thereof that can be deprotected after thepolymerization. For example, the above repeat unit S6-1 can be obtainedby vinyl polymerization of 4-acetoxystyrene followed treatment of theresulting polymer with aqueous base (e.g., ammonium hydroxide) tohydrolyze the acetoxy ester, thereby forming S6-1. Non-limitingexemplary second monomers include those of Scheme 7.

Particularly preferred second monomers for forming a SAP include4-acetoxystyrene (Ac-Sty) and 4-vinylbenzoic acid (4-VBA):

More specific SAP polymers have a structure in accordance with formula(H-5):E′-P′-E″  (H-5),wherein

E′ is a first end group,

E″ is a second end group,

P′ is a polymer chain consisting essentially of:

-   -   i) fluorinated first repeat units selected from the group        consisting of:

combinations thereof, wherein each R′ is an independent radical selectedfrom the group consisting of hydrogen (*—H), methyl (*-Me), ethyl(*-Et), and trifluoromethyl (*—CF₃), and each n′ is an independentinteger having a value of 1 to 12, and

-   -   ii) second repeat units selected from the group consisting of

and combinations thereof, wherein each R″ is independently selected fromthe group consisting of *—H, *-Me, *-Et.

The SAP can have any suitable end group functionality E′ and E″, withthe proviso that wetting properties of the SAP do not adversely affectself-assembly. Non-limiting E′ and/or E″ groups include hydrogen, halide(e.g., fluoride, chloride, bromide, iodide), alkyl groups, alkoxygroups, ester groups, aromatic groups, non-aromatic cyclic groups,groups comprising combinations of the foregoing functionalities, and anyof the foregoing groups substituted with one or more fluorine groups.

E′ and/or E″ of formula (H-5) can comprise 1 to 25 fluorines, moreparticularly 10-25 flourines. In an embodiment, end group E′ and/or E″comprises an ester group comprising 1 to 25 fluorines. Non-limitingexamples of fluorinated ester groups include those of Scheme 8.

A more specific SAP polymer comprises a first end group E′ containing anabove-described fluorinated ester group and a second end group E″ thatis bromide. As an example, Scheme 9 illustrates the ATRPcopolymerization of pentafluorostyrene (PFS) and 4-hydroxystyrene (HOST)to form random copolymer S9-1 using ATRP initiator Pf-OiBr.

In the above notation of Scheme 9, the square brackets indicate the endsof the polymer chain, which is composed of the repeat units enclosed bythe square brackets. The vertical stacking of the repeat units withinthe square brackets indicates a random distribution of the repeat unitsin the polymer chain. In a random distribution of the repeat units, agiven repeat unit whose starred bond overlaps the left square bracketcan be linked to a different one of the repeat units at an atomic centerwhose starred bond overlaps the right square bracket, or to end groupE′, represented in this instance by the moiety derived from Pf-OiBr.Likewise, a given repeat unit whose starred bond overlaps the rightsquared bracket can be linked to an atomic center of a different one ofthe repeat units at an atomic center whose starred bond overlaps theleft square bracket, or to end group E″, represented in this instance bythe bromide group. End group E′ can be linked to any one of the repeatunits at an atomic center having a starred bond overlapping the leftsquare bracket. End group E″ can be linked to any one of the repeatunits at an atomic center having a starred bond overlapping the rightsquare bracket. Subscripts x′ and y′ can represent molar ratio oraverage degree of polymerization (DP) of the corresponding repeat unitenclosed in parentheses.

The SAP can comprise the fluorinated first repeat unit in an amount ofabout 40 mol % to about 90%, preferably about 55 mol % to about 80 mol%, based on total moles of monomers used to form the SAP. The SAP cancomprise the non-fluorinated second repeat unit in an amount of about 10mol % to about 60%, preferably about 20 mol % to about 45 mol % based ontotal moles of monomer used to prepare the SAP.

The SAP can have a number average molecular weight (Mn) of about 1000 toabout 100000, more particularly 2000 to about 50000, and even moreparticularly about 2000 to about 20000. The SAP can have apolydispersity index of about 1.0 to about 3.0.

Random Copolymers for Orientation Control (Underlayer)

In general, the underlayer polymer is a random copolymer capable ofundergoing a reaction to form a covalent bond with another layer of thesubstrate.

For SA materials comprising a polycarbonate block having ester sidechains linked to the carbonate backbone, the underlayer polymer canpotentially be a crosslinkable or brush-type random copolymer of styrene(Sty) and methyl methacrylate (MMA), also referred to aspoly(styrene-r-methyl methacrylate) or P(Sty-r-MMA).

The following discussion pertains to underlayers for high-chi SAmaterials comprising a polycarbonate block having no side chain groups(e.g., a poly(trimethylene carbonate) block (PTMC)) or a polycarbonateblock having carbonate repeat units comprising an alkyl side chain groupof 1-3 carbons (e.g., methyl, ethyl, propyl).

For these high-chi SA materials, the underlayer polymer preferablycomprises a repeat unit comprising an ethylenic backbone portion and aside chain portion comprising a polycarbonate chain. The polycarbonatechain of the side chain can comprise 1 or more carbonate repeat units,preferably 2 to about 40 carbonate repeat units. In an embodiment, thecarbonate repeat unit of the pendant polycarbonate chain of theunderlayer polymer has the same chemical structure as the carbonaterepeat unit of the polycarbonate block of the BCP used in the SA layer(described further below). The underlayer polymers comprising a pendantpolycarbonate chain can be prepared by ring opening polymerization (ROP)of a cyclic carbonate using a polymeric macroinitiator having one ormore pendant hydroxy groups capable of initiating the ROP. The polymericmacroinitiator can be prepared by random polymerization of one or morevinyl polymerizable monomers comprising a pendant alcohol group (e.g.,hydroxyethyl methacrylate, HEMA) or a protected alcohol group that issubsequently deprotected.

I) Underlayers for SA Materials Formed Comprising Trimethylene Carbonate(TMC)

More specifically, the random copolymers for the underlayer comprise afirst repeat unit of formula (A-1):

wherein

R^(x) is a monovalent radical selected from the group consisting of H,methyl, ethyl, and trifluoromethyl (*—CF₃), and

R^(b) is a monovalent radical comprising an aromatic ring.

It should be understood that the two starred bonds of formula (A-1)represent attachment points to other repeat units of the polymer chainor to polymer chain end groups, carbons 1 and 2 are ethylenic carbons ofthe polymer backbone, R^(x) is a first side chain linked to carbon 1 ofthe polymer backbone, and R^(b) is a second side chain linked to carbon1 of the polymer backbone.

Non-limiting R^(b) groups of formula (A-1) include substituted andunsubstituted aryl groups. Exemplary R^(b) groups are listed in Scheme10 below, where the starred bond of the aromatic ring is linked tocarbon 1 of formula (A-1).

In an embodiment, R^(x) of formula (A-1) is hydrogen, and R^(b) isphenyl.

The random copolymers comprise a second repeat unit of formula (A-2):

wherein

R^(x) is a monovalent radical selected from the group consisting of H,methyl, ethyl, and trifluoromethyl (*—CF₃), and

Z′ is a monovalent radical comprising two or more carbonyl-containingfunctional groups independently selected from the group consisting ofester groups, carbonate groups, amide groups, carbamate groups, andcombinations thereof.

It should be understood that R^(x) is a first side chain of the secondrepeat unit which is linked to polymer backbone carbon 1 of formula(A-2), and Z′ is a second side chain of the second repeat unit linked topolymer backbone carbon 1 of formula (A-2).

Second repeat units of formula (A-2) include those obtained fromstyrenes, acrylates, methacrylates, acrylamides, methacrylamides, andthe like, which are modified before or after vinyl polymerization tocomprise the two or more carbonyl-containing functional groups.

More specific Z′ groups of formula (A-2) include those of formula(A-2a):

wherein

L′ is a divalent linking group comprising 2 to 10 carbons,

Q^(a) is *—O—* or *—N(H)—*,

Q^(b) is *—O—* or *—N(H)—*, and

W′ is a group comprising at least one carbon.

The starred bond of formula (A-2a) is linked to carbon 1 of formula(A-2).

Non-limiting examples of Z′ groups of formula (A-2a) include those ofScheme 11.

In an embodiment, Z′ is

Other more specific Z′ groups of formula (A-2) include those of formula(A-2b):

wherein

a′ represents the average number of repeat units and has a value of 1 ormore,

E¹ is a monovalent end group independently selected from the groupconsisting of hydrogen and groups comprising 1 to 10 carbons,

each J′ is an independent monovalent radical selected from the groupconsisting of hydrogen and groups comprising 1 to 10 carbons,

L′ is a divalent linking group comprising 2 to 10 carbons,

Q^(a) is *—O—* or *—N(H)—*,

Q^(b) is *—O—* or *—N(H)—*, and

each R^(a) is an independent monovalent radical selected from the groupconsisting of hydrogen, methyl, and ethyl.

The starred bond of formula (A-2b) is linked to carbon 1 of formula(A-2). The average degree of polymerization, a′, of the Z′ polymer ispreferably 1 to about 40, more preferably 1 to about 20. R^(a) is afirst side chain of the Z′ polymer, and J′ is a second side chain of theZ′ polymer (labeled above).

Non-limiting examples of Z′ groups of formula (A-2b) include those ofScheme 12.

In an embodiment, Q^(a) and Q^(b) are *—O—*, L′ is ethylene(*—CH₂CH₂-*), R^(a) is hydrogen, and J′ is hydrogen of formula (A-2b).In another embodiment, Z′ is

wherein a′ represents the average number of repeat units and has a valueof 1 or more.

Still other more specific Z′ groups of formula (A-2) include those offormula (A-2c):

wherein

a′ represents the average number of repeat units enclosed in theparentheses and has a value of 1 or more,

u′ is 0 or 1,

E¹ is a monovalent end group independently selected from the groupconsisting of hydrogen and groups comprising 1 to 10 carbons,

each J′ is an independent monovalent radical selected from the groupconsisting of hydrogen and groups comprising 1 to 10 carbons,

L^(a) is a divalent linking group comprising 1 to 5 carbons,

each R^(a) is an independent monovalent radical selected from the groupconsisting of hydrogen, methyl, and ethyl, and

when a′ is 1, L^(a), R^(a), J′ and/or E′ comprises a carbonyl-containingfunctional group selected from the group consisting of esters,carbonates, carbamates, and combinations thereof

The starred bond of formula (A-2c) is linked to carbon 1 of formula(A-2). The average degree of polymerization, a′, of the Z′ polymer ispreferably 1 to about 40, more preferably 1 to about 20. R^(a) is afirst side chain of the Z′ polymer, and J′ is a second side chain of theZ′ polymer.

Non-limiting examples of Z′ groups of formula (A-2c) include those ofScheme 13, wherein a′ has an average value of 1 to about 40, and R^(f)is a group comprising 1 to 10 carbons (e.g., methyl, ethyl, propyl,butyl, benzyl).

Non-limiting examples of second repeat units of formula (A-2) includethose of Scheme 13b, wherein a′ has an average value of 1 to about 40,and R^(f) is a group comprising 1 to 10 carbons.

In an embodiment, the second repeat unit of the underlayer randomcopolymer is selected from the group consisting of

combinations thereof, wherein a′ represents degree of polymerization andhas an average value of about 1 to about 40 and R^(f) is a member of thegroup consisting of methyl, ethyl, propyl, phenyl, and benzyl.

The random copolymer for the underlayer preferably comprises a firstrepeat unit:second repeat unit mole ratio between 24:76 to 88:12.

The random copolymer for the underlayer further comprises a third repeatunit of formula (A-3):

wherein

R^(z) is a monovalent radical selected from the group consisting of H,methyl, ethyl, and trifluoromethyl (*—CF₃),

L″ is an independent divalent linking group comprising 1 to 10 carbons,and

K′ is a monovalent electrophilic group capable of reacting with anucleophile to form a covalent bond.

Non-limiting L″ groups of formula (A-3) include ester, amide, aryl,arylester and arylamide groups. Exemplary L″ groups include those listedin Scheme 14 below, where the starred bond of the carbonyl group or thearomatic ring (i.e., the left-most starred bond in each structure) islinked to polymer backbone carbon 1 of formula (A-3).

K′ can comprise an electrophilic group selected from the groupconsisting of active carboxylic ester groups (e.g., p-nitrophenyl ester,pentafluorophenyl ester), halide groups (e.g., chloride, bromide, andiodide), sulfonate esters (e.g., p-toluenesulfonates, mesylates), groupscontaining an epoxide group, and the like. In an embodiment, K′comprises an epoxide group.

More specific *-L″-K′ groups include those of Scheme 15, wherein thestarred bond from the carbonyl group or the aromatic ring is linked tocarbon labeled 1 of formula (A-3).

In an embodiment, R^(z) is methyl of formula (A-3) and L″-K′ is offormula (A-3) is

More specific random copolymers for the underlayer have structures inaccordance with formula (A-4):

wherein

each of subscripts x′, y′, and z′ represents an average number of repeatunits enclosed in the respective parentheses and independently has anaverage value greater than 1,

E′ and E′ are monovalent end groups independently selected from thegroup consisting of hydrogen, halides, and groups comprising 1-10carbons,

each K′ is a monovalent radical capable of reacting with a substratesurface to form a covalent bond,

L′ is a divalent linking group comprising 2 to 10 carbons,

each L″ is an independent divalent linking group comprising 1 to 10carbons,

Q^(a) is *—O—* or *—N(H)—*,

Q^(b) is *—O—* or *—N(H)—*,

each R^(b) is an independent monovalent radical comprising 1 or morearomatic rings,

each of R^(x), R^(y), and R^(z) is a monovalent radical independentlyselected from the group consisting of hydrogen, methyl, ethyl, andtrifluoromethyl (*—CF₃), and

W′ is a group comprising at least one carbon.

In an embodiment, each R^(x) is hydrogen, each R^(b) is phenyl, Q^(a) is*—O—* and Q^(b) is *—O—*. In another embodiment, L′ is ethylene(*—CH₂CH₂—*) and W′ is methyl.

Herein, formula A-4 can also be written as formula (A-5):

Other more specific random copolymers for the underlayer have structuresin accordance with formula (A-6):

wherein

each of subscripts a′, x′, y′, and z′ represents an average number ofrepeat units enclosed in the respective parentheses and independentlyhas an average value greater than 1,

E′ and E″ are monovalent end groups independently selected from thegroup consisting of hydrogen, halides, and groups comprising 1-10carbons,

E¹ is a monovalent end group independently selected from the groupconsisting of hydrogen and groups comprising 1 to 10 carbons,

each J′ is an independent monovalent radical selected from the groupconsisting of hydrogen and groups comprising 1 to 10 carbons,

each K′ is a monovalent radical capable of reacting with a substratesurface to form a covalent bond,

each L′ is a divalent linking group comprising 2 to 10 carbons,

each L″ is an independent divalent linking group comprising 1 to 10carbons,

Q^(a) is *—O—* or *—N(H)—*,

Q^(b) is *—O—* or *—N(H)—*,

each R^(a) is an independent monovalent radical selected from the groupconsisting of hydrogen, methyl, and ethyl,

each R^(b) is an independent monovalent radical comprising 1 or morearomatic rings, and

each of R^(x), R^(y), and R^(z) is a monovalent radical independentlyselected from the group consisting of hydrogen, methyl, ethyl, andtrifluoromethyl (*—CF₃).

In an embodiment, each R^(x) is hydrogen, each R^(b) is phenyl, Q^(a) is*—O—* and Q^(b) is *—O—*, R^(a) is hydrogen, and J′ is hydrogen. Inanother embodiment, L′ is ethylene (*—CH₂CH₂-*) and E¹ is acetyl.

Formula A-6 can also be written as formula (A-7):

Other more specific random copolymers for the underlayer have astructure according to formula (A-8):

wherein

each of x′, y′, and z′ represents the average number of respectiverepeat units enclosed in the respective parentheses, and has an averagevalue greater than 1,

a′ represents the number of respective repeat units enclosed in theparentheses, and has an average value of 1 or more,

E′ and E″ are monovalent end groups independently selected from thegroup consisting of hydrogen, halides, and groups comprising 1-10carbons, and

E¹ is a monovalent end group independently selected from the groupconsisting of hydrogen and groups comprising 1-10 carbons.

Preferably, x′ is 20 to 80, y′ is 1 to 20, z′ is 1 to 5, and a′ is 1 to40. In an embodiment, E¹ is acetyl. In another embodiment, a′ is about 1to about 10.

The structure of formula (A-8) can also be represented by the formula(A-9):

Preparation of Random Copolymers for Orientation Control Layers

A random copolymer for the underlayer can be prepared bycopolymerization of a mixture comprising a vinyl polymerizable monomercomprising an aromatic ring, a second vinyl polymerizable monomercomprising a pendant polycarbonate or polyestercarbonate chain, and athird vinyl polymerizable monomer comprising an electrophilic groupcapable of reacting with a nucleophile to produce a covalent bond. Thismethod is illustrated in Scheme 16 below using the monomers styrene(Sty), HEMA-PTMC, and glycidyl methacrylate (GMA). Catalysts for thevinyl polymerization include radical initiators (e.g.,azobisisobutyronitrile (AIBN)).

HEMA-PTMC can be prepared by an organocatalyzed ring openingpolymerization (ROP) of trimethylene carbonate (TMC) using hydroxyethylmethacrylate (HEMA) as the polymerization initiator, and endcapping theresulting polycarbonate with acetyl chloride, as shown in Scheme 17below. Catalysts for the ROP include organic bases (e.g.,1,8-diazabicyclo[5,4,0]undec-7-ene (DBU)) and phosphate esters (e.g.,diphenyl phosphate (DPP)).

A second method of preparing the random copolymer for the underlayercomprises growing a polycarbonate or polyestercarbonate chain by ringopening polymerization from a nucleophilic site on a side chain of aprecursor random copolymer, as illustrated in Scheme 18.

In this example, the random copolymer of styrene (Sty), hydroxyethylmethacrylate (HEMA), and glycidyl methacrylate GMA), referred to asP(Sty-HEMA-GMA), is a macroinitiator for the ring opening polymerizationof TMC. Each nucleophilic hydroxy group of the macroinitiatorP(Sty-HEMA-GMA) serves as a potential initiating site for ROP of TMC.The resulting polymer is a random graft copolymer comprising a pluralityof side chains bearing a polycarbonate chain.Block Copolymers for Self-Assembly

Block copolymer names can include a “-b-” or “-block-” separating theabbreviated monomer names used to prepare the polymer. The blockcopolymers for self-assembly can comprise two or more blocks, preferably2 to 4 blocks. At least one block comprises a carbonate repeat unit. Forexample, the block copolymer can comprise one polystyrene (PS) block andone polycarbonate (PC) block joined by a linking group. As anotherexample, the block copolymer can comprise two PS blocks and one PC blockjoined by one or two linking groups in the form of a linear polymerchain (i.e., not macrocyclic). As another example, the block copolymercan comprise two PS blocks and two PC blocks joined by one to threelinking groups.

The following discussion is directed to diblock polymers (A-B) but canbe applied to triblock polymers and other block polymer architectures(e.g., star polymers comprising 3 or more polymer arms linked to amulti-valent core, mikto-arm star polymers wherein or more arms comprisedifferent repeat units compared to the other arms).

A first block (block A) comprises a backbone comprising repeatingfunctionalized ethylenic units (e.g., as in a polystyrene backbone). Asecond block (block B) comprises at least one aliphatic carbonate repeatunit (i.e., comprising an aliphatic carbonate group in the polymerbackbone). The blocks are selected so as to be substantially immisciblewith each other. Additionally, it is preferable that the first block andthe second block of the block polymer have the following solubilityproperties with respect to a solvent mixture used to precipitate theblock polymer: i) the first block and the second block are substantiallyinsoluble in a first solvent of the solvent mixture, ii) the first blockis substantially insoluble in a second solvent of the solvent mixture,and iii) the second block is soluble in a second solvent of the solventmixture. That is, the first solvent is a non-solvent for the first blockand the second block, the second solvent is a non-solvent for the firstblock, and the second solvent is a solvent for the second block.

The specific bulk structural units formed by self-assembly of the blockpolymer are determined by the volume ratio of the first block to thesecond block. The volume of a given block means the volume occupied bythe block, which depends on molecular mass of the block. For example,when the volume ratio of the first block A to the second block B isgreater than about 80:20, the block polymer can form an ordered array ofspheres composed of the second block in a matrix composed of the firstblock. When the volume ratio of the first block to the second block isin a range greater than about 80:20, the block copolymer can form anordered array of spheres of the second block in a matrix composed of thefirst block. When the volume ratio of the first block to the secondblock is in a range of about 80:20 to about 60:40, the block polymer canform an ordered array of cylinders composed of the second block in amatrix composed of the first block. When the volume ratio of the firstblock to the second block is less than about 60:40 to about 40:60, theblock polymer can form alternating lamellae (i.e., an array of domainscomposed of the first block alternating with domains composed of thesecond block). As an example, a polystyrene-b-polymethylmethacrylateblock copolymer (PS-b-PMMA) comprising 20% or less by volume of thepolystyrene (PS) block can self-assemble to form PS spheres in apolymethylmethacrylate (PMMA) matrix. As another example, a PS-b-PMMAblock copolymer comprising about 20% to 40% PS by volume canself-assemble to form PS cylinders in a PMMA matrix. The volume ratiobetween the first block and the second block can be adjusted bycontrolling the average molecular weight of each block.

More specifically, the volume ratio of the first block to the secondblock can be about 15:85 to about 85:15, based on the average totalvolume of the block polymer macromolecule. Preferably, for alternatinglamellae formation, the volume ratio of the first block to the secondblock can be about 40:60 to about 60:40, more preferably 45:55 to 55:45,and most preferably 48:52 to 52:48. For cylinder formation, the volumeratio of the first block to second block can be about 74:26 to about63:37, and more preferably about 72:28 to about 65:35.

One of the blocks of the block polymer can be selectively removed (e.g.,by etching techniques) relative to the other block to form structuralfeatures composed of the remaining block using known dry and/or wetetching techniques. The structural features can have any suitable formsuch as, for example, a line pattern, a hole pattern, and/or otherpatterns.

The ROP polymeric initiator is preferably the product of a vinylpolymerization. Vinyl polymerizable monomers include styrenes,acrylates, methacrylates, substituted derivatives thereof, and the like.The vinyl polymerizable monomers can be used singularly or incombination to form the ROP polymeric initiator using any suitablepolymerization technique, including but not limited to free radicalpolymerization, anionic polymerization, cationic polymerization, atomtransfer radical polymerization (ATRP), nitroxide mediatedpolymerization (NMP), and/or reversible addition-fragmentation chaintransfer (RAFT) polymerization.

More specifically, the first block of the block copolymer comprises arepeat unit of formula (B-1):

wherein

R^(w) is a monovalent radical selected from the group consisting of H,methyl, ethyl, and trifluoromethyl (*—CF₃), and

R^(d) is a monovalent radical comprising an aromatic ring linked tocarbon 1.

Non-limiting R^(d) groups of formula (B-1) include substituted andunsubstituted aryl groups. Exemplary R^(d) groups are listed in Scheme19 below, where the starred bond of the carbonyl group or the aromaticring is linked to carbon labeled 1 of formula (B-1).

In an embodiment, R^(w) of formula (B-1) is hydrogen, and R^(d) isphenyl. Repeat units of formula (B-1) can be present singularly or incombination.

The first block can be a homopolymer of a repeat unit of formula (B-1)or a random copolymer chain comprising a combination of repeat units offormula (B-1) and/or a second repeat unit.

The second block of the diblock copolymer comprises at least onealiphatic carbonate repeat unit of formula (B-2):

wherein

R^(e) is an independent monovalent radical selected from the groupconsisting of hydrogen, methyl, and ethyl, and

B″ is an independent monovalent radical selected from the groupconsisting of hydrogen and groups comprising 1 to 40 carbons.

In an embodiment, the polycarbonate block of the block copolymercomprises an ester bearing carbonate repeat unit of formula (B-3):

wherein R^(g) is monovalent hydrocarbon group comprising 1-20 carbons.

In an embodiment R^(g) is a member selected from the group consisting ofmethyl, ethyl, propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl,n-pentyl, neo-pentyl, iso-pentyl, cyclopentyl, norbornyl, cyclohexyl,adamantyl, phenyl, and benzyl. In another embodiment R^(g) is methyl,ethyl, propyl, or benzyl.

More specific block copolymers for self-assembly and directedself-assembly have a structure according to formula (B-4), wherein thesquare brackets represent separate blocks A and B of the blockcopolymer:

wherein

each subscript m′ and n′ represents the average number of respectiverepeat units enclosed in parentheses, and independently has an averagevalue greater than 1,

E² is a monovalent end group selected from the group consisting ofhydrogen and groups comprising 1-10 carbons,

G′ is a monovalent end group selected from the group consisting ofhydrogen, halides, and groups comprising 1-10 carbons,

G″ is a divalent linking group comprising 1-20 carbons,

each B″ is an independent monovalent radical selected from the groupconsisting of hydrogen and groups comprising 1 to 20 carbons,

each R^(d) is an independent monovalent radical comprising an aromaticring,

each R^(w) is an independent monovalent radical selected from the groupconsisting of H, methyl, ethyl, and trifluoromethyl (*—CF₃),

each R^(e) is an independent monovalent radical selected from the groupconsisting of hydrogen, methyl, and ethyl, and

each X″ is an independent divalent radical selected from the groupconsisting of *—O—*, *—S—*, —N(H)—*, and *—N(R″)—*, wherein R″ is amonovalent radical comprising 1 to 6 carbons.

In an embodiment, each B″ is hydrogen, each R^(e) is hydrogen, eachR^(w) is hydrogen, each R^(d) is phenyl, E² is acetyl, and X″ is *—O—*.

A more specific example of a block copolymer for self-assembly has astructure according to formula (B-5):

wherein

each subscript m′ and n′ represents the average number of respectiverepeat units enclosed in parentheses, and independently has an averagevalue greater than 1,

each R^(e) is an independent monovalent radical selected from the groupconsisting of hydrogen, methyl, and ethyl, and

each B″ is an independent monovalent radical selected from the groupconsisting of hydrogen and groups comprising 1 to 20 carbons.

In an embodiment, each R^(e) is hydrogen and each B″ is hydrogen. Inanother embodiment, each R^(e) is methyl and each B″ is *—CO₂Me,*—CO₂Et, *—CO₂Pr (propyl ester), or —CO₂Bn (benzyl ester).

Preparation of the Block Copolymers for Self-Assembly

The block copolymers for self-assembly are preferably prepared by ringopening polymerization of a cyclic carbonate monomer using a polymericinitiator having a backbone derived from a vinyl polymerizable monomer.For diblock and triblock copolymer formation, the polymeric initiatorcan comprise, respectively, 1 and 2 nucleophilic groups (e.g., *—OH,*—NH₂) capable of initiating the ROP of the cyclic carbonyl monomer. TheROP reaction mixture comprises a cyclic carbonyl monomer, a ROPcatalyst, a solvent, and the polymeric initiator. The ROP catalyst ispreferably an acid catalyst (e.g., diphenyl phosphate).

The following methods of forming a diblock copolymer can be applied tothe preparations of triblock polymers and other block polymerarchitectures. The methods provide a block copolymer that issubstantially free of any polycarbonate homopolymer and/or polycarbonaterandom copolymer.

Method 1

This method utilizes a solvent mixture to fractionate an initial blockpolymer formed when the ROP is conducted for a duration timecorresponding to about 50% to 100%, more particularly about 85% to 100%consumption of a cyclic carbonate monomer. For a given set of reactionconditions (e.g., temperature, solvent, type of atmosphere, relativemolar amounts, and other reaction parameters), the consumption of thecyclic carbonate monomer can be monitored using any suitable analyticaltechnique (e.g., proton nuclear magnetic resonance (¹H NMR)).

The ROP produces an initial block polymer containing a living end group,which is a nucleophilic group capable of undergoing further chain growthand/or initiating a ROP of a different cyclic carbonyl monomer.Preferably, the active living end group is deactivated by addition of anendcapping agent to the reaction mixture, thereby terminating thepolymerization and forming an endcapped initial block polymer containinga protected nucleophilic end group. The endcapped initial block polymeris not capable of initiating a ROP. As an example, a polycarbonateformed by ROP of a cyclic carbonate monomer has a living end containinga nucleophilic hydroxy group, which can be deactivated by addition of asuitable acylating agent (e.g., acetic anhydride) to form a protectedhydroxy group (e.g., as an acetyl ester).

The isolated initial block polymer or the endcapped initial blockpolymer (“crude block polymer”) can contain polymeric impurities derivedfrom the cyclic carbonyl monomer that are not covalently linked to thepolymeric initiator. Polymeric impurities can include polycarbonatehomopolymer initiated by traces of water, and/or cyclic polycarbonateformed by backbiting of the living hydroxy end group on thepolycarbonate backbone of the initial block polymer. These impuritiescan adversely affect the self-assembly properties of the initial blockpolymer.

The polymeric impurities can be removed by the following fractionationprocess. A first solution is prepared containing the initial blockpolymer dissolved in a minimal amount of a solvent (e.g., THF) capableof dissolving each block of the block polymer. The first solutioncontains the initial block polymer at a concentration of about 20 wt %based on total weight of the first solution. The first solution is thenadded to an excess amount (about 200 to 400 times the amount of crudepolymer by weight) of a solvent mixture comprising a first solvent and asecond solvent in a volume ratio of about 40:60 to about 60:40,respectively, wherein the first solvent is a non-solvent for the firstblock and the second block, and the second solvent is a non-solvent forthe first block and a solvent for the second block. In an embodiment,the first solvent is MeOH and the second solvent is acetonitrile. Thesolvent mixture selectively dissolves the polymeric impurities, allowingthe final block polymer to precipitate as a solid that can besubstantially free of the polymeric impurities. The fractionationprocedure can be repeated one or more times as necessary to form theblock polymer used for self-assembly applications.

Method 2

In a second method, a trial ROP is performed using the given set ofreaction conditions that includes the polymeric initiator. The amount ofconsumed cyclic carbonyl monomer is monitored (e.g., % consumption) as afunction of ROP duration time t as in Method 1, allowing the ROP toproceed to 85% to 100% consumption of the cyclic carbonyl monomer. Agraph is plotted of the percent consumption of the cyclic carbonate as afunction of ROP duration time t in minutes.

From the scatter plot of the collected data points, a second orderpolynomial function F(t) (i.e., a trendline) can be fitted to theplotted points, wherein F(t) expresses the amount of consumed cycliccarbonyl monomer as a function of ROP duration time t. The R²(R-squared) coefficient for F(t) preferably has a value of about 0.85 to1.0, more preferably 0.9 to 1.0.

Using the expression of F(t), a time t₁ corresponding to 50% consumptionof the cyclic carbonyl monomer can be calculated.

The first derivative of F(t), denoted F′(t), is then calculated for eachmeasurement time t.

The value of F′(t) at 50% cyclic monomer conversion is then determined.Using the value of F′(t₁) at 50% cyclic monomer conversion, ROP durationtimes t₂ and t₃ are determined corresponding to a slope change of −10%and −20% relative to the slope at 50% consumption of cyclic carbonylmonomer.

The ROP is then conducted using the given reaction conditions, stoppingthe ROP at duration time (t′), wherein t₁≦t′≦t₃, and more preferablyt₂≦t′≦t₃. Using these modified reaction conditions, a block polymer forself-assembly can be obtained directly that is free of, or substantiallyfree of, polymer impurities that do not comprise a block derived fromthe polymeric initiator. Optionally, the block polymer can be furthertreated with the solvent mixture as described above under Method 1 toremove any remaining polymeric impurities.

Method 3

In Method 3, the mathematical expression for F′(t) is obtained asdescribed above under Method 2. The value of F′(t) is then calculatedfor each ROP duration time t. Using the values of F′(t), the change inF′(t) between adjacent ROP duration times is calculated for each ROPduration time greater than 0. For example, the change in F′(t) atduration time t_(n), denoted as ΔF′(t_(n)), is equal toF′(t_(n))−F′(t_(n-1)), where n is a positive integer and t_(n)>0.

A second order polynomial trendline D(t) is obtained for a scatter plotof ΔF′(t) as a function of t having the shape of an inverted parabola.D(t) has a first derivative D′(t) equal to zero at some ROP durationtime t″>0 that is less than the duration time corresponding to 100%consumption of the cyclic carbonyl monomer.

The ROP is repeated using the given reaction conditions, terminating theROP at 0.8 t″ to about t″. The resulting final block polymer can be freeof, or substantially free of, polymer impurities that do not comprise ablock derived from the polymeric initiator. Optionally, the blockpolymer can be further treated with the solvent mixture as describedabove under Method 1 to remove any polymeric impurities present.

Cyclic Carbonyl Monomers

Exemplary cyclic carbonyl monomers include cyclic carbonate compounds ofScheme 20, which can be used, for example, to form a polycarbonate blockof the initial block polymer.

Other cyclic carbonyl monomers include cyclic esters (lactones), such asthe compounds of Scheme 21.

The above cyclic carbonyl monomers can be purified by recrystallizationfrom a solvent such as ethyl acetate or by other known methods ofpurification, with particular attention being paid to removing as muchwater as possible from the monomer.

ROP Initiators for the Block Copolymers

Initiators for ring opening polymerizations generally includenucleophilic groups such as alcohols, primary amines, secondary amines,and thiols. Herein, the ROP initiator for the block copolymer is apolymeric initiator comprising a polymer backbone derived from apolymerizable vinyl monomer (styrenes, methacrylates, acrylates,methacrylamides, acrylamides, vinyl esters). An exemplary polymericinitiator is the functionalized polystyrene initiator PS—OH shown below.

The polymeric initiator preferably comprises one or two nucleophilichydroxy groups for initiating a ROP and forming diblock, triblock, andtetrablock copolymers, respectively. In an embodiment, the polymericinitiator comprises two nucleophilic initiating groups, and the blockcopolymer formed by the ROP is a mikto-armed star polymer comprising 4arms. A mikto-arm star polymer has a chemical structure comprising 3 ormore polymer arms linked to a core of the star polymer, and at least onearm has a different polymer composition compared to another of the arms.

The number average molecular weight of the polymeric initiator can befrom 1000 to 1,000,000, more specifically 1000 to 100,000, and even morespecifically, 1000 to 50,000.

An exemplary non-limiting reaction to form a block copolymer isillustrated in Scheme 22 using another macroinitiator AZPS-OH.

Ring Opening Polymerizations (ROP)

The following description of methods, conditions and materials for ringopening polymerizations is applicable to the preparation of the randomcopolymer for orientation control material and/or the block polymer forself-assembly.

The ring-opening polymerization can be performed at a temperature thatis about ambient temperature or higher, 15° C. to 100° C., and morespecifically ambient temperature. Reaction times vary with solvent,temperature, agitation rate, pressure, and equipment, but in general thepolymerizations are complete within about 1 hour to about 48 hours.

The ROP reaction can be performed with or without the use of a solvent,preferably with a solvent. Exemplary solvents include dichloromethane,chloroform, benzene, toluene, xylene, chlorobenzene, dichlorobenzene,benzotrifluoride, petroleum ether, acetonitrile, pentane, hexane,heptane, 2,2,4-trimethylpentane, cyclohexane, diethyl ether, t-butylmethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, or acombination comprising one of the foregoing solvents. When a solvent ispresent, a suitable monomer concentration is about 0.1 to 5 moles perliter, and more particularly about 0.2 to 4 moles per liter.

Whether performed in solution or in bulk, the ROP polymerizations areconducted using an inert (i.e., dry) atmosphere, such as nitrogen orargon, and at a pressure of from 100 to 500 MPa (1 to 5 atm), moretypically at a pressure of 100 to 200 MPa (1 to 2 atm). At thecompletion of the reaction, the solvent can be removed using reducedpressure.

ROP Catalysts

No restriction is placed on the ROP catalyst. Less preferred catalystsfor the ROP polymerization include metal oxides such as tetramethoxyzirconium, tetra-iso-propoxy zirconium, tetra-iso-butoxy zirconium,tetra-n-butoxy zirconium, tetra-t-butoxy zirconium, triethoxy aluminum,tri-n-propoxy aluminum, tri-iso-propoxy aluminum, tri-n-butoxy aluminum,tri-iso-butoxy aluminum, tri-sec-butoxy aluminum,mono-sec-butoxy-di-iso-propoxy aluminum, ethyl acetoacetate aluminumdiisopropylate, aluminum tris(ethyl acetoacetate), tetraethoxy titanium,tetra-iso-propoxy titanium, tetra-n-propoxy titanium, tetra-n-butoxytitanium, tetra-sec-butoxy titanium, tetra-t-butoxy titanium,tri-iso-propoxy gallium, tri-iso-propoxy antimony, tri-iso-butoxyantimony, trimethoxy boron, triethoxy boron, tri-iso-propoxy boron,tri-n-propoxy boron, tri-iso-butoxy boron, tri-n-butoxy boron,tri-sec-butoxy boron, tri-t-butoxy boron, tri-iso-propoxy gallium,tetramethoxy germanium, tetraethoxy germanium, tetra-iso-propoxygermanium, tetra-n-propoxy germanium, tetra-iso-butoxy germanium,tetra-n-butoxy germanium, tetra-sec-butoxy germanium and tetra-t-butoxygermanium; halogenated compounds such as antimony pentachloride, zincchloride, lithium bromide, tin(IV) chloride, cadmium chloride and borontrifluoride diethyl ether; alkyl aluminum such as trimethyl aluminum,triethyl aluminum, diethyl aluminum chloride, ethyl aluminum dichlorideand tri-iso-butyl aluminum; alkyl zinc such as dimethyl zinc, diethylzinc and diisopropyl zinc; tertiary amines such as triallylamine,triethylamine, tri-n-octylamine and benzyldimethylamine; heteropolyacidssuch as phosphotungstic acid, phosphomolybdic acid, silicotungstic acidand alkali metal salts thereof; zirconium compounds such as zirconiumacid chloride, zirconium octanoate, zirconium stearate and zirconiumnitrate. More particularly, the zirconium catalyst can be zirconiumoctanoate, tetraalkoxy zirconium or a trialkoxy aluminum compound.

Preferred ROP catalysts are organocatalysts whose chemical formulascontain no metal. Base organocatalysts for ROPs of cyclic carbonylmonomers include tertiary amines such as triallylamine, triethylamine,tri-n-octylamine and benzyldimethylamine 4-dimethylaminopyridine,phosphines, N-heterocyclic carbenes (NHC), bifunctional aminothioureas,phosphazenes, amidines, and guanidines.

A thiourea ROP organocatalyst isN-(3,5-trifluoromethyl)phenyl-N′-cyclohexyl-thiourea (TU):

Other ROP organocatalysts comprise at least one1,1,1,3,3,3-hexafluoropropan-2-ol-2-yl (HFA) group. Singly-donatinghydrogen bond catalysts have the formula (C-1):R²—C(CF₃)₂OH  (C-1),wherein R² represents a hydrogen or a monovalent radical having from 1to 20 carbons, for example an alkyl group, substituted alkyl group,cycloalkyl group, substituted cycloalkyl group, heterocycloalkyl group,substituted heterocycloalkyl group, aryl group, substituted aryl group,or a combination thereof. Exemplary singly-donating hydrogen bondingcatalysts are listed in Scheme 23.

Doubly-donating hydrogen bonding catalysts have two HFA groups,represented by the general formula (C-2):

wherein R³ is a divalent radical bridging group containing from 1 to 20carbons, such as an alkylene group, a substituted alkylene group, acycloalkylene group, substituted cycloalkylene group, aheterocycloalkylene group, substituted heterocycloalkylene group, anarylene group, a substituted arylene group, or a combination thereof.Representative double hydrogen bonding catalysts of formula (C-2)include those listed in Scheme 24. In a specific embodiment, R² is anarylene or substituted arylene group, and the HFA groups occupypositions meta to each other on the aromatic ring.

Preferred hydrogen bonding catalysts include 4-HFA-St, 4-HFA-Tol, HFTB,NFTB, HPIP, 3,5-HFA-MA, 3,5-HFA-St, 1,3-HFAB, 1,4-HFAB, and combinationsthereof

The HFA catalyst can be bound to a support. In one embodiment, thesupport comprises a polymer, a crosslinked polymer bead, an inorganicparticle, or a metallic particle. HFA-containing polymers can be formedby known methods including direct polymerization of an HFA-containingmonomer (for example, the methacrylate monomer 3,5-HFA-MA or the styrylmonomer 3,5-HFA-St). Functional groups in HFA-containing monomers thatcan undergo direct polymerization (or polymerization with a comonomer)include acrylate, methacrylate, alpha, alpha,alpha-trifluoromethacrylate, alpha-halomethacrylate, acrylamido,methacrylamido, norbornene, vinyl, vinyl ether, and other groups knownin the art. Examples of linking groups include C₁-C₁₂ alkyl groups,C₁-C₁₂ heteroalkyl groups, ether groups, thioether groups, amino groups,ester groups, amide groups, and combinations thereof. Also contemplatedare catalysts comprising charged HFA-containing groups bound by ionicassociation to oppositely charged sites on a polymer or a supportsurface.

Most preferably, the ROP catalyst is an acid organocatalyst (e.g.,diphenylphosphate (DPP), triflic acid, and the like).

The ROP reaction mixture comprises at least one ROP catalyst and, whenappropriate, several ROP catalysts together. The ROP catalyst is addedin a proportion of 1/20 to 1/40,000 moles relative to the cycliccarbonyl monomers, and preferably in a proportion of 1/1,000 to 1/20,000moles relative to the cyclic carbonyl monomers.

ROP Accelerators.

The ROP polymerization can be conducted in the presence of an optionalaccelerator, in particular a nitrogen base. Exemplary nitrogen baseaccelerators are listed below and include pyridine (Py),N,N-dimethylaminocyclohexane (Me₂NCy), 4-N,N-dimethylaminopyridine(DMAP), trans 1,2-bis(dimethylamino)cyclohexane (TMCHD),1,8-diazabicyclo[5.4.0]undec-7-ene (DBU),1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD),7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), (−)-sparteine, (Sp)1,3-bis(2-propyl)-4,5-dimethylimidazol-2-ylidene (Im-1),1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (Im-2),1,3-bis(2,6-di-i-propylphenyl(imidazol-2-ylidene (Im-3),1,3-bis(1-adamantyl)imidazol-2-ylidene (Im-4),1,3-di-i-propylimidazol-2-ylidene (Im-5),1,3-di-t-butylimidazol-2-ylidene (Im-6),1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene (Im-7),1,3-bis(2,6-di-i-propylphenyl)-4,5-dihydroimidazol-2-ylidene,1,3-bis(2,6-di-i-propylphenyl)-4,5-dihydroimidazol-2-ylidene (Im-8) or acombination thereof, shown in Scheme 25.

In an embodiment, the accelerator has two or three nitrogens, eachcapable of participating as a Lewis base, as for example in thestructure (−)-sparteine. Stronger bases generally improve thepolymerization rate.

The catalyst and the accelerator can be the same material. For example,some ring opening polymerizations can be conducted using1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) alone, with no another catalystor accelerator present.

The catalyst is preferably present in an amount of about 0.2 to 20 mol%, 0.5 to 10 mol %, 1 to 5 mol %, or 1 to 2.5 mol %, based on totalmoles of cyclic carbonyl monomer.

The nitrogen base accelerator, when used, is preferably present in anamount of 0.1 to 5.0 mol %, 0.1 to 2.5 mol %, 0.1 to 1.0 mol %, or 0.2to 0.5 mol %, based on total moles of cyclic carbonyl monomer. As statedabove, in some instances the catalyst and the nitrogen base acceleratorcan be the same compound, depending on the particular cyclic carbonylmonomer.

The amount of initiator is calculated based on the equivalent molecularweight per nucleophilic initiator group in the dinucleophilic initiator.The initiator groups are preferably present in an amount of 0.001 to10.0 mol %, 0.1 to 2.5 mol %, 0.1 to 1.0 mol %, and 0.2 to 0.5 mol %,based on total moles of cyclic carbonyl monomer. For example, if themolecular weight of the initiator is 100 g/mole and the initiator has 2hydroxyl groups, the equivalent molecular weight per hydroxyl group is50 g/mole. If the polymerization calls for 5 mol % hydroxyl groups permole of monomer, the amount of initiator is 0.05×50=2.5 g per mole ofmonomer.

In a specific embodiment, the catalyst is present in an amount of about0.2 to 20 mol %, the nitrogen base accelerator is present in an amountof 0.1 to 5.0 mol %, and the nucleophilic initiator groups of theinitiator are present in an amount of 0.1 to 5.0 mol % based on theequivalent molecular weight per nucleophilic initiator group of theinitiator.

The catalysts can be removed by selective precipitation or in the caseof the solid supported catalysts, simply by filtration. The blockpolymer can comprise residual catalyst in an amount of 0 wt % (weightpercent) or more, based on total weight of the block copolymer and theresidual catalyst. The amount of residual catalyst can also be less than20 wt %, less than 15 wt %, less than 10 wt %, less than 5 wt %, lessthan 1 wt %, or most specifically less than 0.5 wt % based on the totalweight of the block copolymer and the residual catalyst.

Endcap Agents

An endcap agent can prevent further chain growth and stabilize thereactive end groups from unwanted side reactions, such as chainscission. Endcap agents include, for example, compounds for convertingterminal hydroxyl groups to esters, such as acid anhydrides (e.g.,acetic anhydride), acid chlorides (acetyl chloride), and/or activeesters (e.g., p-nitrophenyl esters). Other endcap agents include alkyland aryl isocyanates, which form carbamates (urethanes) with terminalhydroxy groups. Other endcap agents include alkylating agents capable offorming alkyl ethers, aromatic ethers including benzyl ethers, silylethers, acetals, ketals, and the like. Still other endcap agents includeperhalogenated (e.g., perfluorinated) derivatives of any of theforegoing endcap agents. In an embodiment, the endcap agent is aceticanhydride, which converts reactive hydroxy end groups to acetate estergroups.

Average Molecular Weight.

The block polymer used for self-assembly preferably has a number averagemolecular weight Mn as determined by size exclusion chromatography of atleast 1500 g/mol, more specifically 1500 g/mol to 1,000,000 g/mol, 4000g/mol to 150000 g/mol, or 4000 g/mol to 50000 g/mol. In an embodiment,the final block polymer has a number average molecular weight Mn of8,000 to 40,000 g/mole.

The block polymer used for self-assembly also preferably has a narrowpolydispersity index (PDI), generally from 1.01 to 2.0, moreparticularly 1.01 to 1.30, and even more particularly 1.01 to 1.25.

Layered Structures

The substrate is a layered structure, which can comprise an orientationcontrol layer (underlayer). The orientation control layer of thesubstrate comprises a covalently bound form of the above-describedrandom copolymer of the underlayer linked to the surface of theunderlying layer of the substrate. The covalently bound random copolymercomprises a divalent first repeat unit of formula (A-1), a divalentsecond repeat unit of formula (A-2), and a trivalent third repeat unitof formula (A-8):

wherein

R^(z) is a monovalent radical selected from the group consisting of H,methyl, ethyl, and trifluoromethyl (*—CF₃),

L″ is an independent divalent linking group comprising 1 to 10 carbons,and

K″ is a divalent linking group, and the starred bond of K″ is covalentlylinked to a surface group of the substrate, and

the first repeat unit, second repeat unit, and third repeat are randomlycovalently bound in the chemical structure of the random copolymer.

An orientation control layer can be formed by disposing on a firstlayered structure (first substrate) a solution containing anabove-described random copolymer for the underlayer, a solvent, andoptionally a member of the group consisting of thermal acid generators(TAGs), photo-acid generators (PAGs), catalysts, and combinationsthereof, and removing the solvent (e.g., by a thermal bake and/orexposure to actinic light), thereby forming a second layer structure(second substrate) comprising an top orientation control layer. Theorientation control layer comprises a covalently bound form of therandom copolymer linked to an underlying layer of the first layeredstructure. Optionally, the second layered structure can be rinsed with asolvent to remove any un-bound random copolymer. The orientation controllayer is neutral wetting with respect to the high-chi block copolymerfor self-assembly, which comprises a polycarbonate block. The thermalbake can be performed at a temperature of about 100° C. to about 250° C.for about 1 second to about 24 hours, preferably about 120° C. to about250° C. for 1 minute to 5 minutes.

Also disclosed are compositions for preparing the SA layers. Thecompositions comprise a solvent, a high-chi block copolymer, and an SAP.The block copolymer and the SAP are dissolved in the solvent. Thecompositions are suitable for forming a film layer (SA layer) comprisingthe block copolymer. The film layer is preferably disposed on anorientation control layer (underlayer). The film layer has a top surfacein contact with the atmosphere. The film layer comprises the blockcopolymer and the polymer additive in non-covalent association.

The following schematic diagrams illustrate methods of formingsubstrates comprising underlayers for orientation control and their usein forming perpendicularly oriented lamellar domain patterns withhigh-chi block copolymers.

FIGS. 1A to 1F are cross-sectional layer diagrams illustrating a processof directed self-assembly of an SA layer comprising a high-chi blockcopolymer and SAP additive, which produces perpendicularly orientedlamellar domains without employing a lithographically preparedtopographic or chemical pre-pattern. It should be understood that thelayers and features are not drawn to scale.

Layered structure 10 of FIG. 1A comprises substrate 11 having substratesurface 12. Substrate 11 can comprise one or more layers (not shown). Asolution comprising a disclosed random copolymer for orientationcontrol, which is dissolved in a suitable solvent, is applied tosubstrate surface 12 (e.g., by spin coating), followed by removal of anysolvent, resulting in layered structure 20 (FIG. 1B), also referred toas a “modified substrate”. Layered structure 20 comprises underlayer 21for orientation control, which comprises the random copolymer bound byat least one covalent bond to substrate 11. Optionally, layeredstructure 20 can be rinsed with a solvent to remove any un-bound randomcopolymer.

Underlayer 21 has underlayer surface 22. A solution comprising adisclosed high-chi block copolymer comprising a polycarbonate block forself-assembly (SA material), a disclosed SAP, and a solvent is appliedto underlayer surface 22 using any suitable technique (e.g., spincoating). Removal of the solvent followed by an optionalpost-application bake (PAB) (e.g., 115° C. for 1 minute) produceslayered structure 30 (FIG. 1C). Layered structure 30 comprises SA layer31 comprising the block copolymer and SAP. SA layer 31 is disposed onunderlayer surface 22. SA layer 31 is then subjected to conditionseffective in inducing the block copolymer to self-assemble (e.g.,annealing layered structure 30 at a temperature of 120° C. to 250° C.for about 1 minute to about 24 hours), thereby forming layered structure40 (FIG. 1D). Layered structure 40 comprises perpendicularly orientedlamellar domain pattern 41 of self-assembled block copolymer disposed onunderlayer surface 22. Domain pattern 41 comprises first lamellar domain43 comprising a first block of the block copolymer (e.g., block A,polystyrene) and second lamellar domain 42 comprising a polycarbonateblock (e.g., block B) of the high-chi block copolymer. Second lamellardomain 42 has a higher concentration of SAP than first lamellar domain43 (not shown). In this instance the lamellae of each of the domainsformed by the block copolymer are in contact with atmosphere interface44 and underlayer surface 22. Self-assembly of SA layer is conductedwith the top surface of SA layer 31 in contact atmosphere interface 44.

One of the domains can be selectively removed (e.g., etched) or modifiedin the presence of the other domain. As an example, dry etching using asuitable gas (02) or wet/chemical etching technique can be used toselectively etch second lamellar domain 42. As another example, firstlamellar domain 43 (polystyrene block) can be selectively etched bymodifying second lamellar domain 42 by i) sequential infiltrationsynthesis (SIS) to infuse metal oxide precursors or ii) by solutioninfiltration of second lamellar domain 42 with metal salts, followed byion-etching of first lamellar domain 43. Selective removal of one of thedomains can also remove underlying orientation control material of theunderlayer (not shown).

Selective removal of one of the domains produces layered structure 50(FIG. 1E) comprising etched domain pattern 51. In this example, etcheddomain pattern 51 comprises first lamellar domain 43 disposed onunderlayer surface 22, and openings 52 (shown). Alternatively, firstlamellar domain 43 can be selectively removed leaving second lamellardomain 42 (not shown). Lamellae of first lamellar domain 43 can havedifferent dimensions after removing second lamellar domain 42 comparedto their dimensions before the selective removal. Openings 52 can have awidth w″ of about 0.5Lo, (e.g., for low-chi SA materials, w″ is about 10nm to about 100 nm). The selective removal process may be carried out bya thermal bake (for thermally decomposable materials), a reactive ionetch process, dissolution in a selective solvent, or a combinationthereof. A chemical modification can be accomplished by a variety ofknown methods. For example, domains can be selectively reacted withsilanes or silyl chlorides to introduce silicon content into a domainand thereby increase its plasma etch resistance. Alternatively, chemicalagents can be used to bind or chemically couple to functional groupsthat are exclusively located in one type of self-assembled domain, toeffect, for example, increased solubility property differences that canadvantageously be used to selectively remove one domain in the presenceof the other domain.

Lastly, etched domain pattern 51 can be transferred to substrate 11,thereby forming layered structure 60 (FIG. 1F) comprising transferpattern 61. Patterned region 61 can be a pattern of lines, holes, pits,and/or a chemically altered state of the underlayer 21 and/or substrate11, which are represented by areas 62. Patterned region 61 can extendinto one or more layers, including the underlayer 21 and/or thesubstrate 11 (shown). The pattern transfer process can further compriseremoval of first lamellar domain 43 (not shown).

FIGS. 2A to 2E are cross-sectional layer diagrams illustrating alithographic process utilizing a pre-formed topographic pre-pattern withthe disclosed underlayer and SA layer comprising a high-chi blockcopolymer and SAP. Layered structure 100 (FIG. 2A) comprises substrate110 comprising underlayer 102 disposed on surface 103 of bottom layer101 (e.g., silicon wafer). Topographic pre-pattern 104 is disposed onunderlayer surface 105. Underlayer 102 comprises a form of the disclosedrandom copolymer bound by at least one covalent bond to surface 103.Bottom layer 101 can comprise one or more sub-layers (not shown).Topographic pre-pattern 104 comprises features 106 (e.g., resistfeatures). Features 106 have sidewalls 107 of height h′, and topsurfaces 108 of width w′. Features 106 are separated by trenches 109(recessed areas) which include bottom surfaces 112 comprising materialof underlayer 102 in contact with an atmosphere. Pre-pattern 104 can beformed by any suitable lithographic technique. Features 106 can compriseany suitable material 111 for directing self-assembly. For example,features 106 can comprise a resist material, which can be a positiveand/or negative tone resist material.

In the present invention, the topography of pre-pattern 104 is notessential for orientation control of the self-assembled lamellar domainsof the high-chi block copolymer. The SA layer is allocated substantiallyor wholly within the trench areas 109 of features 106. Height h′ offeatures 106 is typically greater than or comparable to the thickness ofthe SA layer. Bottom surface 112 is neutral wetting to the SA material(block copolymer), whereas the air interface is not neutral to the SAmaterial. In this example, sidewalls 107 can be neutral wetting ornon-neutral wetting to the block copolymer, with the proviso that thesurface properties of the sidewalls do not adversely affectself-assembly and orientation of the domains formed.

A coating mixture comprising the SA material (a high-chi blockcopolymer) and SAP dissolved in a solvent is applied to topographicpre-pattern 104 using any suitable technique (e.g., spin coating),thereby allocating the mixture substantially or exclusively in trenchareas 109. Topographic pre-pattern 104 is insoluble in or substantiallyinsoluble in the solvent used to prepare the mixture. Removal of thesolvent from the applied coating mixture provides layered structure 120comprising SA layer 121 (FIG. 2B). SA layer 121 comprises regions 122comprising the SA material (high-chi block copolymer) and SAP. SA layer121 is disposed on bottom surfaces 112 of trench areas 109.

Self-assembly of the high-chi block copolymer produces layered structure130 (FIG. 2C) comprising perpendicularly oriented lamellar domainpattern 131. Self-assembly can be spontaneous and/or assisted by athermally treating (annealing) layer 121. Domain pattern 131 comprisesfirst lamellar domain 133 (e.g., PS) having a width of v″, and secondlamellar domain 132 (e.g., polycarbonate) having a width w″ and disposedon bottom surface 112 of trench areas 109. Atmosphere interface 134 isindicated by the arrow. In this example, sidewalls 107 of features 106have preferential affinity for first lamellar domains 133. Therefore,first lamellar domain 133 are positioned in contact with sidewalls 107.First lamellar domain 133 in contact with sidewalls 107 can have a widthof about 0.5 v″. In an embodiment, v″ and w″ are about equal to 0.5Lo.

One of the domains, for example second lamellar domain 132 (e.g.,polycarbonate block), can be selectively removed (e.g., ion-etched) ormodified in the presence of the first lamellar domain 133 (e.g., PSblock) to generate topographical or chemical contrast. Selective removalof one of the domains can also remove underlying orientation controlmaterial (not shown), producing layered structure 140 comprising etcheddomain pattern 141 (FIG. 2D). Etched domain pattern 141 comprises firstlamellar domain 133 disposed on underlayer surface 112, openings 142,and features 106. Openings 142 can have a width w″ of about 0.5Lo (e.g.,for a high-chi block copolymer, w″ can be about 2 nm to about 10 nm).The selective removal process may be carried out by a thermal bake (forthermally decomposable materials), a reactive ion etch process,dissolution in a selective solvent, or a combination thereof. A chemicalmodification may be accomplished by a variety of known methods asdiscussed above. The selective removal process can further removefeatures 106 (not shown).

Finally, etched domain pattern 141 can be transferred to underlayer 102and/or bottom layer 101, thereby forming layered structure 150comprising patterned region 151 (FIG. 2E). Patterned region 151 can be apattern of lines, holes, pits, and/or a chemically altered state of thesubstrate material represented by altered areas 152. Patterned region151 can extend into one or more layers of bottom layer 101. The patterntransfer can be accomplished, for example, by using a reactive ion etchprocess. Features 106 and first lamellar domain 133 can be removedconcomitantly or subsequently to formation of altered areas 152. Theheight of etched domain pattern 141 after the transfer can be less thanthe height of etched domain pattern 141 before the transfer.

The substrate, and more particularly the surface of the substrate, cancomprise inorganic or organic materials such as metals, carbon, orpolymers. More particularly, the substrate can comprise a semiconductingmaterial including, for example, Si, SiGe, SiGeC, SiC, Ge alloys, GaAs,InAs, InP, silicon nitride, titanium nitride, hafnium oxide, as well asother III-V or II-VI compound semiconductors. The substrate can alsocomprise a layered semiconductor such as Si/SiGe, or asemiconductor-on-insulator (SOI). In particular, the substrate cancontain a Si-containing semiconductor material (i.e., a semiconductormaterial that includes Si). The semiconductor material can be doped,non-doped or contain both doped and non-doped regions therein.

The substrate can have an anti-reflection control layer (ARC layer) or abottom ARC layer (BARC layer) to reduce reflectivity of the film stack.Many suitable BARCs are known in the literature including single layerBARCs, dual layer BARCs, graded BARCs, and developable BARCs (DBARCs).The substrate can also comprise a hard mask, a transfer layer (e.g.,planarizing layer, spin-on-glass layer, spin-on carbon layer), and othermaterials as required for the layered device.

Auxiliary Polymers

The substrate, the underlayer and/or the SA layer referred to above caninclude other polymers, referred to as auxiliary polymers. The auxiliarypolymer can be a homopolymer, random copolymer, or block copolymer.

The auxiliary polymers can comprise a hydroxyl group. These includehydroxyl-terminated polymers (e.g., hydroxyl-terminatedpoly(styrene-co-methyl methacrylate and blends of hydroxyl-terminatedpoly(styrene), hydroxyl-terminated poly(methyl methacrylate), andpoly(styrene-b-methyl methacrylate)), hydroxyl-functionalized polymers(e.g., poly(styrene-co-methyl methacrylate-co-2-hydroxyethylmethacrylate)).

Other auxiliary polymers include materials comprising reactive groups,such as those derived from epoxydicyclopentadiene methacrylate, glycidylmethacrylate, or vinyl cinnamates. Exemplary materials comprisingreactive groups include poly(styrene-co-epoxydicyclopentadienemethacrylate), poly(styrene-co-methylmethacrylate-co-epoxydicyclopentadiene methacrylate),poly(styrene-co-methyl methacrylate-co-glycidyl methacrylate),poly(styrene-co-methyl methacrylate-co-vinyl cinnamate)poly(styrene-co-methyl methacrylate-co-vinyl benzocyclobutane), andpoly(alpha-methyl styrene-co-methyl methacrylate)). The reactivepolymers may react as a result of thermal or photochemical treatmenteither alone or in conjunction with an additional crosslinking agent. Inparticular, a catalytic species such as a strongly acidic species may beused to facilitate reaction. The strongly acidic species may be directlyincorporated into a coating composition. Alternatively, a thermal acidgenerator or photoacid generator molecule may be used to generate anacidic species as a result of thermal or photochemical treatment,respectively.

Other non-limiting examples of auxiliary polymers include materials usedin ARC layers, which can include homopolymers and copolymers selectedfrom the group consisting of polybisphenols, polysulfones,polycarbonates, polyhydroquinones, polyphthalates, polybenzoates,polyphenylethers, polyhydroquinone alkylates, polycarbamates,polymalonates and mixtures thereof. These moieties are typicallyfunctionalized in order to tune the required physical properties of thepolymer (optical constants, surface energy). The polymer components canalso contain a plurality of reactive sites distributed along the polymerfor reaction with a crosslinking component. More specific materials usedin ARC layers include poly(4,4′-methylenebisphenol-co-epichlorohydrin),poly(4,4′-ethylidenebisphenol-co-epichlorohydrin),poly(4,4′-isopropylidenebisphenol-co-epichlorohydrin),poly(4,4′-isopropylidenebis[2-methylphenol]-co-epichlorohydrin),poly(4,4′-isopropylidenebis[2,6-dimethylphenol]-co-epichlorohydrin),poly(4,4′-cyclohexylidenebisphenol-co-epichlorohydrin),poly(4,4′-[1-phenylethylidene]bisphenol-co-epichlorohydrin),poly(4,4′-trifluoroisopropylidenebisphenol-co-epichlorohydrin),poly(4,4′-hexafluoroisopropylidenebisphenol-co-epichlorohydrin),poly(4,4′-sulfonylbisphenol-co-epichlorohydrin), poly(bisphenol AFadipic ester), poly(bisphenol AF succinic ester),poly(4,4′-hexafluoroisopropylidenediphthalate-co-epichlorohydrin),poly(4,4′-hexafluoroisopropylidenediphthalate-co-poly(bisphenol AF)),poly(4,4′-hexafluoroisopropylidenebisbenzoate-co-epichlorohydrin),poly(3,3′,4,4′-benzophenonetetracarboxylate-co-epichlorohydrin),poly(4,4′-hexafluoroisopropylidenediphthalate-co-epichlorohydrin-co-2,6-bis[hydroxymethyl]-p-cresol),poly(3,3′,4,4′-benzophenonetetracarboxylate-co-epichlorohydrin-co-2,6-bis[hydroxymethyl]-p-cresol),poly(terephthalate-co-epichlorohydrin),poly(2-nitroterephthalate-co-epichlorohydrin),poly(2-nitrophthalate-co-epichlorohydrin),poly(2-nitroisophthalate-co-epichlorohydrin),poly(hydroquinone-co-epichlorohydrin),poly(methylhydroquinone-co-epichlorohydrin),poly(1,2,4-benzenetriol-co-epichlorohydrin),poly(methylene-bis[4-aminophenyl]-co-glycerol carbamate),poly(isopropylidene-bis[4-aminophenyl]-co-glycerol carbamate),poly(isopropylidene-bis[3-carboxy-4-aminophenyl]-co-glycerol carbamate),poly(methylene-bis[4-hydroxyphenyl]-co-glycerol carbonate),poly(isopropylidene-bis[4-hydroxyphenyl]-co-glycerol carbonate),poly(isopropylidene-bis[3-carboxy-4-hydroxyphenyl]-co-glycerolcarbonate), poly(2-phenyl-1,3-propanediol malonate),poly(2-phenyl-1,3-propanediol 2-methyl-malonate), poly(1,3-propanediolbenzylidene-malonate), poly(2-phenyl-1,3-propanediolbenzylidene-malonate), glycidyl end-capped poly(bisphenolA-co-epichlorohydrin), and silicon-containing anti-reflection coatingA940 from Shin Etsu. Another more specific auxiliary polymer ispoly(styrene-co-epoxydicyclopentadiene methacrylate) random copolymer,P(Sty-r-EDCPMA):

wherein x and y are each integers greater than 1. Other auxiliarypolymers include poly(styrene-co-methylmethacrylate-co-epoxydicyclopentadiene methacrylate),poly(styrene-co-methyl methacrylate-co-glycidyl methacrylate),poly(styrene-co-methyl methacrylate-co-2-hydroxyethyl methacrylate),poly(styrene-co-methyl methacrylate-co-4-vinyl cinammate),poly(styrene-co-methyl methacrylate-co-vinyl benzocyclobutane),poly(styrene-co vinyl benzocyclobutane, poly(alpha-methylstyrene-co-methyl methacrylate), and poly(methyl glutarimide) (PMGI).Other auxiliary polymers comprise polymer brush layers including thoseformed by hydroxyl-terminated poly(styrene-co-methyl methacrylate),poly(styrene-co-methyl methacrylate-co-2-hydroxyethyl methacrylate),hydroxyl-terminated poly(styrene), hydroxyl-terminated poly(methylmethacrylate), poly(styrene-b-methyl methacrylate) block copolymer, andcombinations of the foregoing surface affinity materials. Otherauxiliary polymers include other block copolymers capable of formingself-assembled monolayers.

The coating composition used to prepare the underlayer comprises atleast a solvent and a disclosed random copolymer.

The coating composition used to prepare the SA layer comprising adisclosed block copolymer comprises at least a solvent, a disclosedhigh-chi block copolymer comprising a polycarbonate block, and adisclosed SAP.

The foregoing compositions can additionally comprise other materialsincluding surfactants, polymers, photoacid generators, and thermal acidgenerators. For example, an organosilicate resin can be included in thecomposition for preparing an underlayer.

The compositions for preparing the underlayer and SA layer can beapplied by any suitable method that is compatible with the processes andequipment used in microelectronics fabrication assembly lines. Exemplarynon-limiting techniques include spin-coating, dip-coating, doctorblading, and spray coating.

Exemplary non-limiting casting solvents for preparing theabove-described polymer base coating compositions include toluene,propylene glycol monomethyl ether acetate (PGMEA), propylene glycolmonomethyl ether (PGME), ethoxyethyl propionate, anisole, ethyl lactate,2-heptanone, cyclohexanone, amyl acetate, n-butyl acetate,γ-butyrolactone (GBL), aqueous solutions, acetone, and combinations ofthe foregoing solvents.

The random copolymer for the underlayer has a weight average molecularweight (Mw) of 3,000 to 200,000 g/mol. Similarly, the random copolymerhas a number average molecular weight (Mn) of 1,000 to 80,000. Therandom copolymer can also have a polydispersity (Mw/Mn) of 1.01 to about3.0. Molecular weight, both Mw and Mn, can be determined by, forexample, gel permeation chromatography (GPC) using a universalcalibration method, calibrated to polystyrene standards.

The high-chi block copolymer for the directed self-assembly (SAmaterial) has a weight-average molecular weight (Mw) of 3,000 to 200,000g/mol. Similarly, the high-chi block copolymer can have a number averagemolecular weight (Mn) of 1,000 to 80,000. The high-chi block copolymercan also have a polydispersity (Mw/Mn) of 1.01 to 3.

The surface active polymer (SAP) for the SA layer has a weight-averagemolecular weight (Mw) of 3,000 to 200,000 g/mol. Similarly, the SAP canhave a number average molecular weight (Mn) of 1,000 to 80,000. The SAPcan have a polydispersity (Mw/Mn) of 1.01 to 3.

The morphology (e.g., shape, dimension, and orientation) of theself-assembled domains from block copolymer thin films is a function ofblock copolymer architecture (diblock, triblock, star polymer,bottlebrush block copolymer, mikto-arm polymer, and others), composition(e.g., material, molecular weight, and volume ratio of differentblocks), annealing conditions (e.g., temperature, environment, andannealing time), the interface properties (e.g., polymer-air interfaceand polymer substrate interface) as well as the defined geometry (e.g.,film thickness and topography of the confinement). Therefore, byadjusting one or more parameters, the morphology can be adjusted to theneed of specific applications.

Self-assembly of the high-chi block copolymer (i.e., phase separationand alignment of domains) can occur during film formation, during apost-application bake, or during a subsequent annealing process.Suitable annealing processes include thermal annealing, thermal gradientannealing, solvent vapor annealing or annealing by other gradientfields. More particularly, the SA layer comprising a high-chi blockcopolymer is thermally annealed at a temperature that is above the glasstransition temperature (T_(g)) of the block copolymer but below thedecomposition or degradation temperature (T_(d)) of the block copolymer.The thermal annealing step can be carried out at an annealingtemperature of about 80° C. to about 300° C. The thermal annealing canbe performed for a period of more than 0 hours to about 100 hours, andmore particularly for about 1 hour to about 15 hours. The thermallyannealed block copolymer self-assembles to form ordered domains whoseorientation is perpendicular to the underlying surface plane. Ingeneral, the SA layer can have a thickness of 50 to 10000 angstroms,more particularly 100 to 5000 angstroms, and even more particularly 100to 3000 angstroms.

The difference in the etch rates between two ordered domain regions ofthe block copolymer allows the generation of additional patterns.Selectively removing by etching, solvent or other means, at least oneself-assembled domain, creates a nano-scale relief pattern comprising,for example, a pattern of holes that can be transferred into theunderlying substrate. Types of etching include any common etchingapplied in the manufacture of semiconductor devices, for example,dry-etching such as plasma etching, or wet-etching using selectivesolvents and/or vapors. Typically, dry etching processes are employedfor etching at sub-50 nm dimensions. Prior to this patterndevelopment/pattern transfer, the self-assembled layer of SA materialcan be optionally chemically modified to improve properties necessaryfor pattern transfer, such as etch resistance or mechanical properties.

The relief pattern of openings formed by selective removal of one of thedomains can have a spatial frequency greater than that of a topographicpre-pattern used with the high-chi block copolymer.

Etch resistant materials can be applied to a substrate surface,underlayer surface, surface of a resist feature, and/or a domain patternof the block copolymer for control of relative etch rates. Theetch-resistant material can be deposited from the vapor phase by aprocess including, chemical vapor deposition (CVD), plasma enhanced CVD,atomic layer deposition (ALD), sequential infiltration synthesis (SIS),sequential infiltration of metal salts, sputtering, thermal evaporation,electron beam evaporation, pulsed laser deposition, or other suitabledeposition method that is compatible with the processes and equipmentused in microelectronics fabrication.

Also disclosed is a film comprising the self-assembled high-chi blockpolymer, the film comprising lamellar domains having a perpendicularorientation relative to the plane of the film. Further disclosed is alayered structure comprising substrate that includes an underlayer, anda film of self-assembled high-chi block copolymer disposed on theunderlayer, the film comprising lamellar domains having a perpendicularorientation relative to the plane of the film. In an embodiment, thelayered structure is a semiconductor device.

The above-described processes can be used to form layered structurescomprising metal wiring lines, holes for contacts or vias, insulationsections (e.g., damascene trenches or shallow trench isolation), andtrenches for capacitor structures suitable for the design of integratedcircuit devices. The method is especially useful in the context ofcreating patterned layers of oxides, nitrides or polysilicon.

The above-described methods advantageously allow self-assembledstructures having reduced feature width and increased periodicity. Thedomain feature width can be from 1 nm to about 30 nm, from 5 nm to about18 nm, or more particularly from 5 nm to about 15 nm.

The following non-limiting examples are provided to further illustratethe disclosed polymers and their use in forming self-assembled layers.

EXAMPLES

Materials used in the following examples are listed in Table 1.

TABLE 1 ABBREVIATION DESCRIPTION SUPPLIER AcCl Acetyl ChlorideSigma-Aldrich AIBN Azobisisobutyronitrile Sigma-Aldrich Anisole AnisoleSigma-Aldrich AZPS1-OH Hydroxyl-end-functional AZ Electronicpolystyrene, Mn 6200 Materials AZPS2-OH Hydroxyl-end-functional AZElectronic polystyrene, Mn 10000 Materials AZPS3-OHHydroxyl-end-functional AZ Electronic polystyrene, Mn 4200 MaterialsBisMPA Dimethylolpropionoic acid Perstorp BriBr α-Bromoisobutyrylbromide Sigma-Aldrich BzOH Benzyl alcohol Sigma-Aldrich CuBr Copper (I)bromide Sigma-Aldrich DBU 1,8-Diazabicyclo[5,4,0]undec- Sigma-Aldrich7-ene DCM Dichloromethane Sigma-Aldrich DPP Diphenyl phosphateSigma-Aldrich EtG Ethylene glycol Sigma-Aldrich EtG Ethylene glycolSigma-Aldrich EtiBr Ethyl α-bromoisobutyrate Sigma-Aldrich GMA Glycidylmethacrylate, MW 142.2 Sigma-Aldrich HEMA Hydroxyethyl methacrylate,Sigma-Aldrich MW 130.14 HFA-Sty Hexafluoroalcohol Styrene Central GlassChemical Company Lac 3,6-Dimethyl-1,4-dioxane- Sigma-Aldrich 2,5-dioneMe6TREN Tris[2-(dimethylamino)ethyl]amine Sigma-Aldrich MeOH MethanolSigma-Aldrich p-NBT p-Nitrobenzyltosylate Sigma-Aldrich OH-PSI1-OHHydroxyl-end-functional Polymer Source polystyrene, Mn 11000, DP = 108Inc,, Montreal Pf-OH 1H,1H-Perfluorononan-l-ol Synquest Labs PFSPentafluorostyrene Sigma-Aldrich PHOST Poly(4-hydroxystyrene) Mn 5480,Nippon Soda Co. PDI = 1.08. PMDETA N,N,N′,N′,N″-pentamethyldi-Sigma-Aldrich ethylenetriamine Si Gel Silica Gel Sigma-Aldrich StyStyrene, MW 104.15 Sigma-Aldrich TEA Triethylamine Sigma-Aldrich THFTetrahydrofuran Sigma-Aldrich TMC Trimethylene carbonate RichmanChemicals Tol Toluene Sigma-Aldrich P(Sty-r-MMA)- Hydroxy-terminatedpoly(styrene- AZ Electronics OH r-methyl methacrylate) random copolymer

Herein, Mn is the number average molecular weight, Mw is the weightaverage molecular weight, and MW is the molecular weight of onemolecule.

Cyclic carbonate monomer MTC-Me was prepared as previously reported (Y.Zoul et al., Polymer, 45(16), 5459-5463; 2004).

Example 1

Synthesis of diblock polymer DBP1, n=57, m=75.

Diblock polymer DBP1, n=57, m=75 was prepared by ring openingpolymerization (ROP) of trimethylene carbonate (TMC) using mono-alcoholinitiator AZPS1-OH and ROP acid catalyst diphenylphosphate (DPP). To anoven dried 20 mL round bottom flask equipped with a magnetic stir bar,AZPS1-OH (0.70 g, 0.113 mmol, Mn=6200, PDI=1.02, n=57, obtained fromAZ-Electronic Materials, Branchburg, N.J.), TMC (1.76 g, 17.25 mmol),and dichloromethane (DCM, 2.94 mL) were added. The reaction mixture wasstirred until the AZPS1-OH macroinitiator and TMC were completelydissolved in DCM, upon which diphenylphosphate (DPP, 400 mg, 1.6 mmol,catalyst) was added. The reaction mixture was stirred at roomtemperature (r.t.) for 16 hours in a glove box. The reaction flask wasbrought out of the glove box and cooled at 0° C. by immersing it in anice-water bath. The reaction was stopped by adding DCM (6 mL),triethylamine (TEA, 0.7 mL, 02.72 mmol) and acetyl chloride (0.25 ml,3.52 mmol). The reaction was further stirred for two hours at roomtemperature. The resulting polymer was isolated by precipitating thereaction mixture in methanol. The product was collected in a frit funnelby removing methanol under vacuum and the resulting solids wereredissolved in THF to form a 20 wt % solution and reprecipitated inmethanol. The solid was collected in a frit funnel and dried undervacuum at 40° C. for two hours to obtain the resulting compound. Mn(GPC)=17200, Mw=17700, PDI=1.029; Mn (NMR)=AZPS(6.2k)-PMTC(7.8k),n=57.4, m=75; TMC % conversion: about 50%. The resulting polymer wasdissolved in THF to form a 20 wt % solution and the polymer wasprecipitated in methanol:acetonitrile (200 mL, 60:40 v/v). Theprecipitated solids and the solvents were collected in a centrifuge tubeand the solids were collected by centrifuging at 4000 RPM at 0° C.followed by decanting the solvent and drying the solids in a vacuum ovenat 40° C. for two hours to give DBP1. Mn (GPC)=17200, Mw=17600,PDI=1.02; Mn (NMR)=PS(6.2k)-b-PTMC(7.7k), n=57, m=75. The notationPS(6.2k)-b-PTMC(7.7k) means the poly(styrene) block (PS) has an Mn=6200and the poly(trimethylene carbonate) block (PTMC) has an Mn=7700. Thisnotation is also used in the examples that follow.

Example 2

Synthesis of diblock polymer DBP2, n=96, m=82.

Diblock polymer DBP2, n=96, m=82 was prepared by ring openingpolymerization (ROP) of methyl carbonate (MTC-Me), with mono-alcoholinitiator AZPS2-OH and ROP base catalyst DBU. To an oven dried 4 mLglass vial equipped with a magnetic stir bar, AZPS2-OH (0.10 g, 0.01mmol, Mn=10000, PDI=1.05, n=96), obtained from AZ-Electronic Materials,Branchburg, N.J.), MTC-Me (0.31 g, 1.80 mmol), and DCM (1.80 mL) wereadded. The reaction mixture was stirred until the AZPS2-OHmacroinitiator and MTC-Me were completely dissolved in DCM, upon whichcatalyst (DBU, 1.5 mg, 0.01 mmol, 10 wt % solution in toluene) wasadded. The reaction mixture was stirred at room temperature (r.t.) for 3hours in a glove box. The reaction flask brought out of the glove boxand cooled at 0° C. by immersing it in an ice-water bath. The reactionwas stopped by adding DCM (1 mL), TEA (0.1 mL, 0.39 mmol) and acetylchloride (0.025 ml, 0.352 mmol). The reaction was further stirred fortwo hours at room temperature. The resulting polymer was isolated byprecipitating the reaction mixture in methanol. The product wascollected in a frit funnel by removing methanol under vacuum and theresulting solids were redissolved in THF to form a 20 wt % solution andreprecipitated in methanol. The solid was collected in a frit funnel anddried under vacuum at 40° C. for two hours to obtain the resultingcompound. Mn (GPC)=24040, Mw=26224, PDI=1.09; Mn(NMR)=AZPS(10.0k)-PMTC-Me(16.9k), n=96, m=97; MTC-Me % conversion: about57%. The resulting polymer was dissolved in THF to form a 20 wt %solution and the polymer was precipitated in methanol:acetonitrile (20mL, 80:20 v/v). The precipitated solids and the solvents were collectedin a centrifuge tube and the solids were collected by centrifuging at4000 RPM at 0° C. followed by decanting the solvent and drying thesolids in a vacuum oven at 40° C. for two hours to give DBP2. Mn(GPC)=25700, Mw=27400, PDI=1.06; Mn of each block byNMR=PS(10k)-b-PMTC-Me(14.2k), n=96, m=84.

Example 3 Synthesis of triblock polymer TBP1

To an oven dried 4 mL vial equipped with a magnetic stir bar, OH-PSI1-OH(0.15 g, 0.013 mmol, Mn=11,500, n=108, obtained from Polymer SourceIncorporated, Montreal, Canada), TMC (0.378 g, 3.70 mmol), and DCM (1.85mL) were added. The reaction mixture was stirred until the HO-PSI1-OHmacroinitiator and TMC were completely dissolved in DCM, upon which DPP(65 mg, 0.26 mmol) was added. The reaction mixture was stirred at roomtemperature for 15 hours in a glove box. The reaction was stopped byadding DCM (1 mL), TEA (0.2 mL) and acetyl chloride (0.1 mL). Thereaction was further stirred for two hours at room temperature. Theresulting polymer was isolated by precipitating the reaction mixture inmethanol. The product was collected in a frit funnel by removingmethanol under vacuum and the resulting solids were redissolved in THFto form a 20 wt % solution and reprecipitated in methanol. The solid wascollected in a frit funnel and dried under vacuum at 40° C. for twohours to obtain the resulting compound. The resulting polymer wasdissolved in THF to form a 20 wt % solution and the polymer wasprecipitated in methanol:acetonitrile (200 mL, 60:40 v/v). Theprecipitated solids and the solvents were collected in a centrifuge tubeand the solids were collected by centrifuging at 4000 RPM at 0° C.followed by decanting the solvent and drying the solids in a vacuum ovenat 40° C. for two hours. Mn (GPC)=27900, Mw=30300, PDI=1.09; Mn of eachblock by NMR=PTMC(7.05k)-b-PS(11.5k)-b-PTMC(7.05 k), n=108, m=138. Thevolume fraction of the PTMC block, expressed as VfPTMC, was about 0.49.

Table 2 summarizes the preparations and properties of the blockcopolymers of Examples 1-3.

TABLE 2 GPC NMR (Mn, kDa)) Vf Ex- BCP Mono- Cata- Time Mn Mw PSCarbonate Carbo- ample Name mer lyst Initiator Temp (hours) (kDa) (kDa)PDI block block nate 1 DBP1 TMC DPP AZPS1-OH r.t. 16 17.2 17.6 1.02  6.2 7.7 0.49 2 DBP2 MTC-Me DBU AZPS2-OH r.t.  3 25.7 27.4 1.06 10k 14.20.47 3 DBP3 TMC DPP OH-PSI1- r.t. 15 27.9 30.3 1.09 11.5 14.1 0.49 OHUnderlayer random copolymers based on styrene, TMC, and GMA

Example 4

Synthesis of intermediate random copolymer P-1, Sty:HEMA:GMA mole ratiox:y:z=88:6:6, Sty:HEMA:GMA, DP ratio x′:y′:z′=50.5:3.5:3.5, used as amacroinitiator further below.

In the above notation, the vertical stacking of the repeat units withinthe square brackets indicates a random distribution of the repeat unitsin the polymer chain. End group E′ is linked to one of the starred bondsoverlapping the left square bracket. End group E″ is linked to one ofthe starred bonds overlapping the right square bracket. It should beunderstood that for a given repeat unit, a starred bond that overlapsthe left square bracket can be linked to a different repeat unit at theposition indicated by the right starred bond overlapping the rightsquare bracket, or to end group E′. Likewise, for a given repeat unit, astarred bond that overlaps the right square bracket can be linked to adifferent repeat unit at the position indicated by the left starred bondoverlapping the left square bracket, or to end group E″. Unlessotherwise indicated, subscripts x′, y′, and z′ represent the averagenumber of the corresponding parenthesized repeat unit in the polymer.For P-1, the end groups E′ and E″ are not shown.

Styrene (Sty, 14.4 g, 138.0 mmol), hydroxy ethyl methacrylate (HEMA, 1.0g, 7.68 mmol), glycidyl methacrylate (GMA, 1.09 g, 7.66 mmol), THF (50g), and azobisisobutyronitrile (AIBN, 0.757 g, 4.61 mmol, 3 mol % basedon total moles of vinyl monomers) were combined in a 250 mL round bottomflask (RBF) equipped with a magnetic stir-bar and an overhead condenser.The reaction mixture was stirred at 70° C. for 18 hours and was stoppedby cooling the reaction to room temperature. The resulting polymer wasisolated by two precipitations in MeOH, and was dried under vacuum at50° C. for 24 hours. Mn=6200, Mw=8700, PDI=1.40. The productSty:HEMA:GMA mole ratio x:y:z was calculated by ¹³C inverse gated NMR asx:y:z=88:6:6. Based on the Mn and the product mole ratio, the degree ofpolymerization (DP) of each repeat units Sty:HEMA:GMA was calculated forP-1 to be x′:y′:z′=50.5:3.5:3.5, respectively.

The random copolymers of Examples 5-14 have the prefix “G1” in the namewere prepared from macroinitiator P-1.

Example 5

Synthesis of TMC-functional random graft copolymer G1-1 frommacroinitiator P-1 (Example 4, STY:HEMA:GMA molar ratio x:y:z=88:6:6, DPratio x′:y′:z′=50.5:3.5:3.5) for orientation control.

The quantity y′a′ (i.e., y′ multiplied by a′) represents the totalaverage number of repeat units derived from TMC in the random graftcopolymer G1-1. In these calculations, Mn was not adjusted for the massof end groups E′ and E″ when determining the DP of each repeat unit.

P-1 (0.2 g, Example 4), trimethylene carbonate (TMC, 0.060 g, 0.588mmol) and dichloromethane (DCM, 0.2 g) were added to an oven dried 4 mLglass vial equipped with a magnetic stir bar. The reaction mixture wasstirred until the macroinitiator and TMC were completely dissolved inDCM, upon which 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, ˜10 mg) wasadded. The reaction mixture was stirred at room temperature (r.t.) for 1hour in a glove box. The reaction was stopped by bringing the reactionvial out of the glove box and by adding DCM (0.5 ml), triethylamine(TEA, 0.27 g, 2.72 mmol) and acetyl chloride (˜60 mg, 0.764 mmol). Thereaction was further stirred for two hours at room temperature. Theresulting polymer was isolated by precipitating the reaction mixture inmethanol. The product was collected in a frit funnel by removingmethanol under vacuum and the resulting solids were redissolved in THFto form a 20 wt % solution and reprecipitated in methanol for two moretimes. The solids were collected in a frit funnel and dried under vacuumat 40° C. for two hours to obtain random graft copolymer G1-1, where theSty:TMC mole ratio x′:y′a′=73:27 was determined by ¹H NMR. The averagevalue of a′ was calculated as follows:

x′/y′=50.5/3.5 (DP ratio of the P-1 macroinitiator),

x′/(y′a′)=73/27 (Sty:TMC mole ratio of G1-1 by ¹H NMR),

rearranging, x′/y′=73a′/27

substituting, 50.5/3.5=73a′/27, and

solving, a′=5.33.

Therefore, G1-1 has a side chain polycarbonate having an average numberof carbonate repeat units a′=5.33, based on the Mn of G1-1.

Examples 6-15

Preparation of underlayer random graft copolymers G1-2 to G1-11 fororientation control. These polymers were prepared using the generalprocedure of Example 5 and macroinitiator P-1 (Example 4) at variousSty:TMC molar ratios. G1-2 to G1-11 differ from G1-1 by a′, the averagenumber of repeat units of TMC in the side chain.

Table 3 summarizes the preparation of Examples 5-15.

TABLE 3 Random Graft P-1 Sty:TMC Monomer Polymer TMC DCM DBU InitiatorTime GPC Mole % Ex. Name (g) (g) (mg) (g) Temp (hours) Mn Mw PDI Ratioa′¹ Conversion. 5 G1-1 0.06 0.2 ~10 0.2 r.t. 1 — — — 73:27 5.3 >99 6G1-2 0.1 0.32 ~10 0.2 r.t. 1.5 — — — 60:40 9.6 >99 7 G1-3 0.46 1.50 ~100.2 r.t. 2 23600 44000 1.87 24:76 45.7 >99 8 G1-4 0.035 0.52 ~10 0.2r.t. 0.45 — — — 88:12 2.0 >99 9 G1-5 0.06 0.37 ~13 0.2 r.t. 1 9300 135001.44 73:27 5.3 >99 10 G1-6 0.1 0.45 ~10 0.2 r.t. 1.5 11400 18000 1.5759:41 10.0 >99 11 G1-7 0.06 0.72 ~10 0.2 r.t. 1 — — — 73:27 5.3 >99 12G1-8 0.1 0.9 ~10 0.2 r.t. 1.4 — — — 66:34 7.4 ~90 13 G1-9 0.15 0.9 ~160.2 r.t. 1 12100 15900 1.31 62:38 8.8 ~50 14  G1-10 0.15 0.9 ~14 0.2r.t. 0.75 — — — 62:38 8.8 ~50 15  G1-11 0.15 0.9 ~14 0.2 r.t. 1.4 — — —43:57 19.1 ~65 ¹a′ is based on Mn of the random graft copolymer, withoutcorrecting for end groupsSynthesis of underlayers based on styrene, AcEMA, and GMA

These random copolymers (Examples 16-22) have the prefix “GHS” in thename and have the general structure

where average numbers of repeat units x′, y′ and z′ are greater than 0.End groups E′ and E″ are not shown.

Example 16

Synthesis of poly(styrene-r-acetoxyethyl methacrylate-r-glycidylmethacrylate) underlayer GHS-1, x:y:z=77:19:4 (mole ratio), DP ratiox′:y′:z′=48.5:12.1:2.6.

Styrene (Sty, 4.0 g, 38.4 mmol, MW 104.2), acetoxyethyl methacrylate(AcEMA, 1.21 g, 7.02 mmol, MW 172.2), glycidyl methacrylate (GMA, 0.20g, 1.40 mmol, MW 142.2), THF (22 g), and azobisisobutyronitrile (AIBN,0.31 g, 1.87 mmol, 4 mol % based on total moles of vinyl monomers) werecombined in a 250 mL round bottom flask (RBF) equipped with a magneticstir-bar and an overhead condenser. The reaction mixture was stirred at70° C. for 18 hours and was stopped by cooling the reaction to roomtemperature. The resulting polymer was isolated by two precipitations inMeOH, and was dried under vacuum at 50° C. for 24 hours to give GHS-1.Mn=7500, Mw=10,100, PDI=1.34. The product mole ratio of Sty:AcEMA:GMAwas calculated by ¹³C inverse gated NMR as x:y:z=77:19:4 (mole ratio).Based on Mn and without adjusting for end groups E′ and E″, the degreeof polymerization ratio of Sty:AcEMA:GMA was x′:y′:z′=48.5:12.1:2.6, or48:12:3 when rounded to zero decimal places.

Examples 17-22

Preparation of random graft copolymers GHS-2 to GHS-7 for underlayerorientation control. These polymers were prepared using the generalprocedure of Example 16 at various Sty:AcEMA:GMA molar ratios.

Table 4 summarizes the preparations of Examples 16-22.

TABLE 4 Random Graft Sty AcEMA GMA AIBN Feed Polymer (g, (g, (g, (g, THFTemp Time Mole Ratio Examples Name mmol) mmol) mmol) mmol) (g) (° C.)(hours) Sty:AcEMA:GMA 16 GHS-1 4.0, 1.21, 0.20 0.31, 22 70 18 82:15:338.4 7.02 1.40 1.87 17 GHS-2 1.40, 1.61, 0.1, 0.154, 10 70 18 57:40:313.33 9.38 0.70 0.94 18 GHS-3 0.66, 2.82, 0.10, 0.154, 11 70 18 27:70:36.33 16.41 0.70 0.94 19 GHS-4 1.27, 1.82, 0.10, 0.154, 10 70 18 52:45:312.20 10.55 0.70 0.94 20 GHS-5 1.20, 1.94, 0.1, 0.154, 10 70 18 49:48:311.5 11.25 0.70 0.94 21 GHS-6 0.55, 1.05, 0.05, 0.077, 5 70 18 42:52:35.2 6.1 0.35 0.47 22 GHS-7 0.66, 0.87, 0.05, 0.077, 5 70 18 54:43:3 6.325.04 0.35 0.47 Product Mole Ratio Product GPC Examples Sty:AcEMA:GMASty:AcEMA:GMA DP ratio Mn Mw PDI 16 77:19:4 49:12:3 7500 10100 1.34 1755:42:2 29:22:1 6900 12100 1.74 18 29:68:3 15:36:2 8100 14600 1.79 1950:47:3 7200 11870 1.64 20 48:49:3 7570 12860 1.69 21 45:50:4 27:30:28400 13700 1.63 22 53:44:3 31:26:2 7900 12900 1.62Synthesis of surface active polymer additives (SAP)

Example 23

Synthesis of PSAP1-40, a protected random copolymer ofpentafluorostyrene (PFS) and acetoxystyrene (Ac-Sty).

Pentafluorostyrene (PFS, 3.0 g, 15.45 mmol, MW 194), acetoxystyrene(Ac-Sty, 3.75 g, 23.18 mmol, MW 162.19), tetrahydrofuran (THF, 20 g),and azobisisobutyronitrile (AIBN, 0.25 g, 1.54 mmol, 4 mol % based ontotal moles of vinyl monomers) were combined in a 100 mL round bottomflask (RBF) equipped with a magnetic stir-bar and an overhead condenser.The reaction mixture was stirred at 70° C. for 18 hours and was stoppedby cooling the reaction to room temperature. The resulting polymer wasisolated by two precipitations in hexanes, and was dried under vacuum at50° C. for 24 hours. The resulting polymer was used directly fordeprotection as described below (Example 28) and was not furthercharacterized.

Examples 24-26

Synthesis of PSAP1-60, PSAP1-80, and PSAP1-90, respectively. Theserandom copolymers of PFS and Ac-Sty were prepared using the generalprocedure of Example 23 at various molar ratios of PFS and Ac-Sty.

Example 27

Synthesis of PSAP2-60.

Tridecafluoro methacrylate (TDFMA, 1.50 g, 3.47 mmol, MW 432),acetoxystyrene (Ac-Sty, 0.375 g, 2.31 mmol, MW 162.19), THF (7.50 g),and azobisisobutyronitrile (AIBN, 38 mg, 0.23 mmol, 4 mol % based ontotal moles of vinyl monomers) were combined in a 100 mL round bottomflask (RBF) equipped with a magnetic stir-bar and an overhead condenser.The reaction mixture was stirred at 70° C. for 18 hours and was stoppedby cooling the reaction to room temperature. The resulting polymer wasisolated by two precipitations in methanol, and was dried under vacuumat 50° C. for 24 hours. The polymer was not further characterized andwas used directly for deprotection as described below.

Table 5 summarizes the preparations of protected surface active polymerExamples 23-27 prepared by free radical polymerization using AIBNinitiator.

TABLE 5 PSAP Monomer 1 Monomer 2 AIBN additive Feed (g, Feed (g, THFTime Ex. name Name (g, mmol) Mole % Name mmol) Mole % mmol) (g) Temp(hours) 23 PSAP1- PFS 3.0, 40 Ac-Sty 3.75, 60 0.25, 20 70 18 40 15.4523.18 0.1.54 24 PSAP1- PFS 4.50 60 Ac-Sty 2.52 40 0.25, 20 70 18 6023.18 15.44 0.1.54 25 PSAP1- PFS 6.01 80 Ac-Sty 1.25, 20 0.25, 20 70 1880 30.97 7.74 0.1.54 26 PSAP1- PFS 6.63, 90 Ac-Sty 0.63, 10 0.25, 20 7018 90 34.89 3.87 0.1.54 27 PSAP2- TFDMA 1.50, 60 Ac-Sty 0.375, 40 0.038,7.5 70 18 60 3.47 2.31 0.23

Example 28

Deprotection of PSAP1-40 of Example 23 to form SAP1-40

To a 100 ml round bottom flask equipped with a magnetic stir bar and areflux condenser, PSAP1-40 (1.50 g, Example 23) was added. To thisflask, methanol (20 ml) was added to create a suspension of the polymer.Ammonium hydroxide solution (2.1 g, 28.0-30.0 wt % solution in water)was added to the vessel and the reaction was heated at 70° C. for 18hours. The resulting polymer was precipitated in 1000 ml of water spikedwith 2-3 ml of acetic acid. The solids were collected and redissolved inTHF followed by re-precipitation in water. The resulting solid was driedunder vacuum at 80° C. for 24 hours. Mn=16000, Mw=26000, PDI=1.65. Theproduct PFS:hydroxystyrene x:y mole ratio was calculated by ¹³C inversegated NMR as x:y=44:56 (mole ratio). Based on Mn and excluding endgroups E′ and E″, the DP ratio x′:y′=46:59.

Examples 29-32

Deprotection of PSAP1-60, PSAP1-80, PSAP1-90 and PSAP2-60, respectively.These random copolymers were deprotected using the general procedure ofExample 28. The perfluorinated ester of PSAP2-60 was stable to thehydrolysis conditions.

Example 33 Synthesis of SAP3-80

Pentafluorostyrene (PFS, 1.50 g, 15.45 mmol, MW 194), 4-vinyl benzoicacid (4-VBA, 0.286 g, 23 mmol, MW 162.19), THF (20 g), andazobisisobutyronitrile (AIBN, 0.25 g, 1.54 mmol, 4 mol % based on totalmoles of vinyl monomers) were combined in a 100 mL round bottom flask(RBF) equipped with a magnetic stir-bar and an overhead condenser. Thereaction mixture was stirred at 70° C. for 18 hours and was stopped bycooling the reaction to room temperature. The resulting polymer wasisolated by two precipitations in hexanes, and was dried under vacuum at50° C. for 24 hours. Mn=11000, Mw=14900, PDI=1.35. The product PFS:4VBAx:y mole ratio was calculated by ¹³C inverse gated NMR as x:y=84:16(mole ratio). Based on Mn and excluding end groups E′ and E″, the DPratio x′:y′=49.5:9.4.

Table 6 summarizes the NMR and GPC analyses of surface active polymerExamples 28-33.

TABLE 6 SAP SAP SAP additive Monomer 1 Monomer 2 Monomer 1:Monomer 2Monomer 1:Monomer 2 GPC Ex. name Name Name Mole Ratio DP Ratio Mn Mw PDI28 SAP1-40 PFS HOST 44:56 46:59 16.0k 26.0k 1.65 29 SAP1-60 PFS HOST57:43 16.1k 24.7k 1.52 30 SAP1-80 PFS HOST 80:20 8.7k 14.2k 1.62 31SAP1-90 PFS HOST 89:11 11.0k 15.6k 1.45 32 SAP2-60 TFDMA HOST 33 SAP3-80PFS 4-VBA 84:16 49.5:9.4  11.0k 14.9k 1.35 HOST = repeat unit formedfrom deprotection of acetoxystyrene (“hydroxystyrene”).Underlayer and Composite Layer Film Preparations

Examples 34-40

Thin film preparation of underlayers (ULs) with random graft copolymersG1-2, G1-3, G1-7, G1-8 and G1-10 (see above Table 3).

The following general procedure was used to prepare a thin filmunderlayer on a silicon wafer. A solution was prepared by dissolving therandom graft copolymer (95 parts by weight) and p-nitrobenzyl tosylate(p-NBT, 5 parts by weight) in propylene glycol monomethyl ether acetate(PGMEA, 10,000 parts by weight) to form a 1.0 wt % solution based ontotal dry solids. p-NBT is a thermal acid generator and was added topromote the grafting and partial crosslinking of a thin film of therandom graft copolymer on the silicon wafer substrate when baked(annealed). The solutions were passed through a 0.2 mmpolytetrafluoroethylene (PTFE) filter prior to spin coating the solutionon a silicon wafer at 2000 rpm spin rate. After forming the thin film,the coated wafer was baked at 200° C. for 3 minutes and cooled to roomtemperature. The initial baked thin film (underlayer) had a thickness of20 nm, measured with a Nanospec Reflectometer. The underlayer was thengiven a solvent rinse by casting PGMEA on top of the coated wafer,letting the solvent puddle for 30 seconds, and spin drying the treatedwafer at 2000 rpm for 30 seconds. The rinse was intended to remove anyexcess random graft copolymer that was not crosslinked or grafted to thewafer surface. The final film thickness of the underlayer was 10 nmafter the solvent rinse. Table 7 summarizes the underlayer films UL-1 toUL-5 and UL-13 to UL-14 prepared with the random copolymers having a“G1” prefix in the name.

TABLE 7 DP¹ UL Random Sty:TMC Sty HEMA TMC Example Name Copolymer moleratio (x′) (y′) (a′) 34 UL-1 G1-3 24:76 50.5 3.5 45.7 35 UL-2 G1-2 60:4050.5 3.5 9.6 36 UL-3  G1-10 62:38 50.5 3.5 8.8 37 UL-4 G1-8 66:34 50.53.5 7.4 38 UL-5 G1-7 73:27 50.5 3.5 5.3 39  UL-13  G1-11 43:57 50.5 3.58.8 40  UL-14 G1-4 88:12 50.5 3.5 19.1 ¹x′, y′, and a′ are based on Mnof the random graft copolymer

Examples 41-47

Thin film preparation of underlayers (ULs) using random copolymers GHS-1to GHS-7 (see above Table 4).

The following general procedure was used to prepare a thin filmunderlayer on a silicon wafer. A solution was prepared by dissolving therandom graft copolymer (95 parts by weight) and p-nitrobenzyl tosylate(p-NBT, 5 parts by weight) in propylene glycol monomethyl ether acetate(PGMEA, 10,000 parts by weight) to form a 1.0 wt % solution based ontotal dry solids. The solutions were passed through a 0.2 mmpolytetrafluoroethylene (PTFE) filter prior to spin coating the solutionon a silicon wafer at 2000 rpm spin rate. After forming the thin film,the coated wafer was baked at 190° C. for 3 minutes and cooled to roomtemperature. The initial baked thin film (underlayer) had a thickness of20 nm, measured with a Nanospec Reflectometer. The underlayer was thengiven a solvent rinse by casting PGMEA on top of the coated wafer,letting the solvent puddle for 30 seconds, and spin drying the treatedwafer at 2000 rpm for 30 seconds. The rinse was intended to remove anyexcess random graft copolymer that was not crosslinked or grafted to thewafer surface. The final film thickness of the underlayer was 10 nmafter the solvent rinse. Table 8 summarizes the underlayer films UL-6 toUL-12 prepared with GHS-1 to GHS-7, respectively.

TABLE 8 UL Random Sty:AcEMA:GMA Sty:AcEMA:GMA Example Name Copolymermole ratio DP ratio 41 UL-6 GHS-1 77:19:4 49:12:3 42 UL-7 GHS-2 55:43:229:22:1 43 UL-8 GHS-3 29:68:3 15:36:2 44 UL-9 GHS-4 50:47:3 45 UL-10GHS-5 48:49:3 46 UL-11 GHS-6 45:50:4 27:30:2 47 UL-12 GHS-7 53:44:331:26:2

Examples 48-52

Thin film preparation of underlayers (ULs) using P(Sty-r-MMA)-OH randomcopolymer brushes obtained from AZ Electronic Materials.

The following general procedure was used to prepare a thin filmunderlayer on a silicon wafer. P(Sty-r-MMA)-OH, a hydroxy-terminatedpoly(styrene-r-methyl methacrylate) random copolymer brush material, wasreceived from AZ Electronic Materials in the form of a solution in PGMEA(solution code NLD-303). The solution was used as received. The polymersolution was spin coated with 2000 rpm on a silicon wafer. The coatedwafer was baked at 250° C. for 2 minutes prior to a solvent rinse toform UL-15. Table 9 summarizes the underlayer films UL-15 to UL-19prepared with P(Sty-r-MMA)-OH random copolymer brush materials, whereSty=styrene and MMA=methyl methacrylate.

TABLE 9 UL P(Sty-r-MMA)-OH Sty:MMA Example Name Name mol % 48 UL-15NLD-303  0:100 49 UL-16 NLD-328J 20:80  50 UL-17 NLD-320 30:70  51 UL-18NLD-321 40:60  52 UL-19 NLD-322 47:53 

Formulation of block copolymer and SAP additives

Examples 53-65

Preparation of coating formulations for self-assembly using blockcopolymers of Examples 1-3 and surface active polymers (SAP) of Examples28-33.

The following general procedure is representative. Separate blockcopolymer solutions were prepared for one coating. The block copolymer(0.01 g) for self-assembly was dissolved in PGMEA (0.823 g) to form a1.2 wt % solution of the block copolymer. Surface active polymer (0.1 g,one of SAP Examples 28-33) was dissolved in PGMEA (8.23 g) to form a 1.2wt % stock solution of the SAP polymer based on total weight of thesolution. The SAP solution was filtered through 0.2 micrometer PTFEfilter. A portion of the SAP stock solution was then added to the entireblock copolymer solution containing to form a coating compositioncontaining the desired SAP concentration. This solution was stirred atroom temperature to form a homogeneous mixture upon which it wasfiltered through a 0.2 micrometer PTFE filter. Table 10 summarizes theprepared block copolymer coating formulations containing SAP additives.

TABLE 10 Coating Formulation SAP BCP SAP wt % Each Block Stock Stock ofBCP BPC BCP Mn (NMR) SAP SAP Sol'n Sol'n SAP BCP PGMEA total Example Ex.Name Type (k = x1000) Name Example (g) (g) (mg) (g) (g) solids 53 1 DBP1Diblock 6.2k-7.7k SAP1- 28 0.833 0.042 0.504 0.01 0.865 5 40 54 1 DBP1Diblock 6.2k-7.7k SAP1- 29 0.833 0.042 0.504 0.01 0.865 5 60 55 1 DBP1Diblock 6.2k-7.7k SAP1- 30 0.833 0.042 0.504 0.01 0.865 5 80 56 1 DBP1Diblock 6.2k-7.7k SAP1- 31 0.833 0.042 0.504 0.01 0.865 5 90 57 1 DBP1Diblock 6.2k-7.7k SAP1- 30 0.833 0.025 0.300 0.01 0.848 3 80 58 1 DBP1Diblock 6.2k-7.7k SAP1- 30 0.833 0.083 0.996 0.01 0.905 10 80 59 1 DBP1Diblock 6.2k-7.7k SAP1- 31 0.833 0.025 0.300 0.01 0.848 3 90 60 1 DBP1Diblock 6.2k-7.7k SAP1- 31 0.833 0.083 0.996 0.01 0.905 10 90 61 2 DBP2Diblock 10.0k-14.3k SAP1- 30 0.833 0.012 0.144 0.01 0.865 1.5 80 62 3TBP1 Triblock 7.05k-11.5k-7.05k SAP1- 30 0.833 0.008 0.096 0.01 0.831 180 63 3 TBP1 Triblock 7.05k-11.5k-7.05k SAP1- 30 0.833 0.025 0.300 0.010.848 3 80 64 3 TBP1 Triblock 7.05k-11.5k-7.05k SAP2- 32 0.833 0.0250.300 0.01 0.848 3 60 65 3 TBP1 Triblock 7.05k-11.5k-7.05k SAP3- 330.833 0.042 0.504 0.01 0.865 5 80

Thin film self-assembly of formulated block copolymer compositions onUL-1 to UL-14.

Examples 66-78

The following general procedure was used to prepare thin films offormulated block copolymers on UL-1 to UL-14 substrates. A selectedcoating formulation prepared in Examples 53-65 was spin coated on aselected underlayer coated substrate of Examples 34-47 at a spin rate of2000 rpm. The coated wafer was then baked (annealed) at a temperature of140° C. or 170° C. for 5 minutes and immediately cooled to roomtemperature. The formulated block copolymer films were characterized byatomic force microscopy (AFM) using a Digital Instruments 3100 AFM witha 1 N/m spring constant silicon nitride cantilever operated in a tappingmode. Scan size and speed were set at 2 micrometer×2 micrometer area and1 Hz respectively.

Table 11 summarizes the coating and annealing conditions of the filmsprepared in Examples 66-78.

TABLE 11 BCP Thin Film layer for Self-Assembly Coating/AnnealingConditions BCP SAP Spin Film Underlayer Formulation BCP Mn of each SAPwt % of Spin Speed time Annealing Annealing Example Name Example Nameblock (k = x1000) name dry solids RPM Sec Temp ° C. Time (min) 66 UL-253 DBP1 6.2k-7.7k SAP1-40 5 2000 30 170 5 67 UL-2 54 DBP1 6.2k-7.7kSAP1-60 5 2000 30 170 5 68 UL-2 55 DBP1 6.2k-7.7k SAP1-80 5 2000 30 1705 69 UL-2 56 DBP1 6.2k-7.7k SAP1-90 5 2000 30 170 5 70 UL-2 57 DBP16.2k-7.7k SAP1-80 3 2000 30 170 5 71 UL-2 58 DBP1 6.2k-7.7k SAP1-80 102000 30 170 5 72 UL-2 59 DBP1 6.2k-7.7k SAP1-90 3 2000 30 140 5 73 UL-260 DBP1 6.2k-7.7k SAP1-90 10 2000 30 140 5 74  UL-16 61 DBP2 10k-14.2kSAP1-80 1.5 2000 30 170 5 75 UL-2 62 TBP1 7.05k-11.5k- SAP1-80 1 2000 30140 5 7.05k 76 UL-2 63 TBP1 7.05k-11.5k- SAP1-80 3 2000 30 140 5 7.05k77 UL-2 64 TBP1 7.05k-11.5k- SAP2-60 3 2000 30 140 5 7.05k 78 UL-2 65TBP1 7.05k-11.5k- SAP3-80 5 2000 30 140 5 7.05k

Table 12 summarizes the atomic force microscopy height images obtainedwith the self-assembled films prepared on various underlayers and themorphologies obtained by self-assembly. “I/H” means islands/holes (notdesirable). “Partially ⊥ lamellae” means about 20% to less than 70% ofthe regions of the film contained perpendicular lamellae (notdesirable). “⊥ lamellae” means 95% to 100% of the regions of the filmcontained perpendicular lamellae (most desirable). “Flat” means therewas no discernible structure in the film.

TABLE 12 Self-Assembled Thin Film Layer BCP Each SAP UnderlayerUnderlayer Formulation BCP Block Mn SAP wt % of Thin Film Example NamePolymer Example Name (k = x1000) Name dry solids Morphology 66 UL-2 G1-253 DBP1 6.2k-7.7k SAP1-40 5 I/H 67 UL-2 G1-2 54 DBP1 6.2k-7.7k SAP1-60 5I/H 68 UL-2 G1-2 55 DBP1 6.2k-7.7k SAP1-80 5 ⊥ lamellae 69 UL-2 G1-2 56DBP1 6.2k-7.7k SAP1-90 5 Partially ⊥ lamellae 70 UL-2 G1-2 57 DBP16.2k-7.7k SAP1-80 3 Partially ⊥ lamellae 71 UL-2 G1-2 58 DBP1 6.2k-7.7kSAP1-80 10 I/H 72 UL-2 G1-2 59 DBP1 6.2k-7.7k SAP1-90 3 I/H 73 UL-2 G1-260 DBP1 6.2k-7.7k SAP1-90 10 ⊥ lamellae 74  UL-16 NLD-328J 61 DBP-10k-14.2k SAP1-80 1.5 ⊥ lamellae 2 75 UL-2 G1-2 62 TBP1 7.05k-11.5k-SAP1-80 1 Partially ⊥ lamellae 7.05k 76 UL-2 G1-2 63 TBP1 7.05k-11.5k-SAP1-80 3 ⊥ lamellae 7.05k 77 UL-2 G1-2 64 TBP1 7.05k-11.5k- SAP2-60 3 ⊥lamellae 7.05k 78 UL-2 G1-2 65 TBP1 7.05k-11.5k- SAP3-80 5 ⊥ lamellae7.05k

FIGS. 3-15 are atomic force microscopy (AFM) images of theself-assembled block copolymer films of Examples 66-78, respectively.Film layers containing SAP1-80, SAP1-90, SAP2-60 and SAP3-80 producedperpendicular lamellae at SAP concentration of 1.5 wt % to 10 wt % basedon total dry solids of the formulation used to prepare the SA layer.SAP1-80 was effective in producing perpendicular lamellae when used inamounts of 1.5 wt % with diblock copolymer DBP2 on underlayer UL-16.SAP1-80, SAP2-60, and SAP3-80 were effective in producing perpendicularlamellae when used in amounts of 3 wt % with triblock copolymer TBP1 onunderlayer UL-2.

Graphoepitaxy Directed Self-Assembly (DSA)

Example 79

In this example, a topographic pre-pattern was formed on a neutralunderlayer (UL-2) using a negative tone photoresist, followed by coatinga thin film of formulated block copolymer onto the pre-pattern. Theblock copolymer was substantially confined to the trenches of the resistpre-pattern. The coated structure was then annealed, allowing thepre-pattern to direct self-assembly of the block copolymer.

An underlayer solution was prepared by dissolving the random graftcopolymer G1-2 (0.095 g, 95 parts by weight) and p-nitrobenzyl tosylate(p-NBT, 0.005 g, 5 parts by weight) in propylene glycol monomethyl etheracetate (PGMEA, 9.90 g, 10,000 parts by weight) to form a 1.0 wt %solution based on total weight of the solution. The thermal acidgenerator p-NBT was added to promote the grafting and partialcrosslinking of a thin film of the random graft copolymer on a siliconwafer substrate stack. The silicon wafer substrate stack comprised asilicon wafer bottom layer coated with ˜30 nm thick amorphous carbonlayer and 10 nm thick silicon nitride (SiN_(x)) layer. The underlayersolution was passed through a 0.2 micrometer polytetrafluoroethylene(PTFE) filter prior to spin coating the solution on the silicon waferstack at 2000 rpm spin rate. After forming the thin film, the coatedwafer was baked at 200° C. for 3 minutes and cooled to room temperature.The initial baked thin film (underlayer) had a thickness of 20 nm,measured with a Nanospec Reflectometer. The underlayer was then given asolvent rinse by casting PGMEA on top of the coated wafer, letting thesolvent puddle for 30 seconds, and spin drying the treated wafer at 2000rpm for 30 seconds. The rinse was intended to remove any excess randomgraft copolymer that was not crosslinked or grafted to the wafersurface. The final film thickness of the underlayer was 10 nm after thesolvent rinse.

Next, a 60 nm thick layer of a commercial 193 nm negative-tonephotoresist (JSR ARF7210JN-8) was disposed on this underlayer coatedsubstrate followed by post application bake at 80° C. for 60 seconds.The photoresist layer was then exposed using a 193 nm immersioninterference tool (IBM NEMO) with fixed dose of 4.67 mJ, baked at 95° C.for 60 sec, and developed for 60 seconds with 2-heptanone developer. Theresulting 200 nm pitch patterned photoresist layer was then hard bakedat 200° C. for 3 min prior to coating a block copolymer formulation.

The block copolymer formulation was prepared as follows. Diblockcopolymer DBP1 (0.01 g) was dissolved in PGMEA (1.24 g, 10,000 parts byweight) to form a 0.8 wt % stock solution of the block copolymer basedon total weight of the solution. The solution was passed through a 0.2micrometer polytetrafluoroethylene (PTFE) filter. A separate stocksolution was prepared by dissolving SAP1-80 additive (0.1 g) in PGMEA(12.4 g) at 0.8 wt % SAP based on total weight of the solution. The SAPsolution was passed through a 0.2 micrometer PTFE filter. A desiredamount of SAP stock solution (see Table 13) was added to the blockcopolymer solution and the mixture was stirred well to form a homogenoussolution. The resulting solution containing block copolymer and SAP wasspin coated on the patterned photoresist substrate described above.After spin coating, the coated wafer was baked at a 170° C. for 5minutes, and immediately cooled to room temperature. The self-assembleddomains of the block copolymer inside the guiding pre-pattern trencheswere analyzed with top down and cross section SEM. The samples wereetched with tetrafluoroethylene (CF₄/H₂) gas using RIE for 5 seconds onthe top surface for top-down SEM and were subjected to perpendicularetch for 8 seconds at the cross section of the film for cross-sectionSEM. The samples were subjected to 20 seconds of Au sputtering with 20mA current prior to SEM imaging.

Table 12 summarizes the block copolymer formulation of Example 79.

TABLE 13 Coating Formulation SAP Stock Sol'n SAP SAP BCP Solution 0.8 wt% BCP Sol'n wt % UL BCP BCP SAP SAP Sol'n Amount BCP SAP PGMEA of dryExample Name Example. Name Ex. Name (g) (g) (g) (mg) (g) solids 79 UL-21 DBP1 27 SAP1-80 1.250 0.1075 0.01 0.860 1.347 8.6

FIG. 16 is a set atomic force microscopy (AFM) images at twomagnifications of the self-assembled block copolymer film of Example 79,showing perpendicular lamellae were formed in the trench areas of theresist pattern.

Block copolymer formulations without SAP additives

Examples 80-82 (Comparative)

Coating formulations using the block copolymers of Examples 1-3 wereprepared without SAP additives. The following general procedure isrepresentative. A 1.2 wt % solution of block copolymer in PGMEA wasprepared as described above, and the resulting solution was filteredthrough a 0.2 micrometer PTFE filter.

Table 14 summarizes the block copolymer formulations of Examples 80-82prepared without SAP additive.

TABLE 14 BCP BCP BCP amount PGMEA Coating Formulation Example ExampleName (g) (g) wt % BCP 80 1 DBP1 0.01 0.83 1.2 81 2 DBP-2 0.01 0.83 1.282 3 TBP1 0.01 0.83 1.2Thin-film self-assembly of block copolymers formulations without SAPadditives

Examples 83-85 (Comparative)

The following general procedure was used to prepare thin films of blockcopolymer formulation Examples 80-82 lacking the SAP additive on variousunderlayer coated substrates. The coating formulation solution was spincoated on the underlayer coated substrates at the desired spin rate(Table 15). After forming the thin film, the coated wafer was baked atthe specified time and temperatures and immediately cooled to roomtemperature. The block copolymer films were characterized by atomicforce microscopy (AFM) using a Digital Instruments 3100 AFM with a 1 N/mspring constant silicon nitride cantilever operated in a tapping mode.Scan size and speed were set at 2 micrometers×2 micrometers area and 1Hz respectively.

Table 15 summarizes the coating and annealing conditions used inExamples 83-85 and the resulting morphologies of the block copolymerthin film after self-assembly.

TABLE 15 Coating and BCP Annealing conditions BCP Spin Spin FormulationBCP speed time Annealing Annealing BCP Example Underlayer Example NameRPM (Sec) temp (° C.) time (min) Morphology 83 UL-2 80 DBP1 2000 30 1705 I/H 84  UL-16 81 DBP2 2000 30 170 5 I/H 85 UL-2 82 TBP1 2000 30 170 5Flat

Each of the films of Table 15 displayed island/hole or parallel cylindermorphology (undesirable). FIGS. 17-19 are AFM height images of Examples83-85, respectively.

Oleic Acid as Surface Active Material

Examples 86-93 (Comparative)

Thin film preparation and characterization of formulated block copolymercompositions with oleic acid or decafluorosuberic acid (DFS) asadditives on substrates having underlayer UL-3.

The following general procedure was used to prepare thin films offormulated diblock copolymer DBP1 (Example 1) with oleic acid ordecafluorosuberic acid (DFS) on UL-2 substrates. A solution of DBP1 wasprepared by dissolving the block copolymer (0.01 g) in PGMEA (0.823 g)to form a 1.2 wt % solution based on total dry solids. The solutionswere passed through a 0.2 micrometer polytetrafluoroethylene (PTFE)filter. A desired amount of oleic acid or decafluorosuberic acid (DFS)was added to the block copolymer solutions made above and the mixturewas stirred well to form a homogenous solution prior to spin coating theformulated block copolymer solution on the underlayer coated substratesat the desired spin rate. After forming the thin film, the coated waferwas baked at a specified time and temperature (Table 16) and immediatelycooled to room temperature. The formulated block copolymer films werecharacterized by atomic force microscopy (AFM) using a DigitalInstruments 3100 AFM with a 1 N/m spring constant silicon nitridecantilever operated in a tapping mode. Scan size and speed were set at 2micrometer×2 micrometer area and 1 Hz respectively.

Table 16 summarizes the formulated block copolymer thin filmself-assembly on UL-2 and the obtained morphologies. All the samples ofTable 16 showed island/hole (I/H) morphology. FIGS. 20-27 are AFM heightimages of Examples 86-93, respectively.

TABLE 16 Block Annealing Conditions Copolymer Additive Spin SpinAnnealing UL Block Conc. (wt Additive wt % of dry Speed time AnnealingTime Thin Film Example Name Copolymer %) Name solids RPM (Sec) Temp ° C.(min) Morphology 86 UL-3 DBP1 1.2 Oleic 1 2000 30 140 5 I/H Acid 87 UL-3DBP1 1.2 Oleic 5 2000 30 140 5 I/H Acid 88 UL-3 DBP1 1.2 Oleic 10 200030 140 5 I/H Acid 89 UL-3 DBP1 1.2 Oleic 20 2000 30 140 5 I/H Acid 90UL-3 DBP1 1.2 DFS 5 2000 30 140 5 I/H 91 UL-3 DBP1 1.2 DFS 10 2000 30140 5 I/H 92 UL-3 DBP1 1.2 DFS 20 2000 30 140 5 I/H 93 UL-3 TBP1 1.2Oleic 5 2000 30 170 5 I/H Acid

These results indicate that the surface active non-fluorinatedcarboxylic acid (oleic acid) and the fluorinated carboxylic acid (DFS)were not effective additives in forming perpendicular oriented lamellae.

Examples 94-95 (Comparative)

Thin film preparation using SAP additives having only non-fluorinatedhydrogen-bond donating groups (Example 94) or only fluorinatednon-hydrogen-bond donating groups (Example 95). The substrates utilizedunderlayer UL-2.

A solution of DBP1 was prepared by dissolving the block copolymer (0.01g) in PGMEA (0.823 g) to form a 1.2 wt % solution based on total drysolids. The solutions were passed through a 0.2 micrometerpolytetrafluoroethylene (PTFE) filter. A desired amount ofpoly(4-hydroxystyrene) (PHOST, Nippon Soda Company Ltd., Mn=5480,PDI=1.08) or PSAP1-80 from Example 25 (before deprotection) was added tothe block copolymer solutions made above and the mixture was stirredwell to form a homogenous solution prior to spin coating the formulatedblock copolymer solution on the underlayer coated substrates at thedesired spin rate. After forming the thin film, the coated wafer wasbaked at the desired time and temperatures and immediately cooled toroom temperature. The formulated block copolymer films werecharacterized by atomic force microscopy (AFM) using a DigitalInstruments 3100 AFM with a 1 N/m spring constant silicon nitridecantilever operated in a tapping mode. Scan size and speed were set at 2micrometer×2 micrometer area and 1 Hz respectively. Table 17 summarizesthe formulated block copolymer thin film self-assembly on UL-2 and theobtained morphologies. The samples of Table 17 showed either island/holeor partially perpendicular lamellae morphology. FIGS. 28-29 are AFMheight images of Examples 94-95, respectively.

TABLE 17 Block Annealing Conditions Copolymer Spin Spin Annealing ULBlock Conc. (wt Additive Additive Speed time Annealing Time Thin FilmExample Name Copolymer %) Name wt % of dry solids RPM Sec Temp ° C.(min) Morphology 94 UL-2 DBP1 1.2 PHOST 5 2000 30 140 5 I/H 95 UL-2 DBP11.2 PSAP1-80 5 2000 30 140 5 Partially ⊥ Example lamellae 25

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. When a range is used to express apossible value using two numerical limits X and Y (e.g., a concentrationof X ppm to Y ppm), unless otherwise stated the value can be X, Y, orany number between X and Y.

The description of the present invention has been presented for purposesof illustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention. Theembodiments were chosen and described in order to best explain theprinciples of the invention and their practical application, and toenable others of ordinary skill in the art to understand the invention.

What is claimed is:
 1. A composition, comprising: i) a solvent; ii) ablock copolymer comprising: a) a first block comprising a repeat unit offormula (B-1):

wherein I) R^(w) is a monovalent radical selected from the groupconsisting of H, methyl, ethyl, and trifluoromethyl (*—CF₃) and II)R^(d) is a monovalent radical comprising an aromatic ring linked tocarbon 1, and b) an aliphatic polycarbonate second block (polycarbonateblock) linked to the first block; and iii) a surface active polymer(SAP), comprising: about 40 mol % to about 90 mol %, based on totalmoles of monomers used to prepare the SAP, of a fluorinated repeat unit(first repeat unit), wherein the first repeat unit has a chemicalstructure having no functionality capable of donating a hydrogen to forma hydrogen bond, about 10 mol % to about 60 mol %, based on total molesof monomers used to prepare the SAP, of a non-fluorinated second repeatunit comprising a functional group selected from the group consisting ofalcohols, carboxylic acids, phosphonic acids, and sulfonic acids;wherein the block copolymer and the SAP are dissolved in the solvent. 2.The composition of claim 1, wherein the composition is suitable forforming a layer for self-assembly (SA layer) disposed on an underlayerof a substrate, wherein the SA layer comprises the block copolymer andthe SAP in non-covalent association, the SA layer has a top surface incontact with an atmosphere, the underlayer is neutral wetting to theblock copolymer, the block copolymer of the SA layer is capable ofself-assembly to form a phase separated domain pattern having acharacteristic pitch Lo, the domain pattern comprises alternatingdomains comprising respective chemically distinct blocks of the blockcopolymer, each of the domains has contact with the underlayer and theatmosphere, and a domain comprising the polycarbonate block(polycarbonate domain) has a higher concentration of the SAP compared toa domain comprising the first block of the block copolymer.
 3. Thecomposition of claim 2, wherein the polycarbonate domain has lowersurface energy compared to an otherwise identical polycarbonate domainlacking the SAP.
 4. The composition of claim 2, wherein the domainpattern comprises lamellar domains, and each of the lamellar domains hasa perpendicular orientation to the underlayer.
 5. The composition ofclaim 2, wherein the domain pattern comprises cylindrical domains, andeach of the cylindrical domains has a central axis orientedperpendicular to the underlayer.
 6. The composition of claim 1, whereinthe SAP is a random copolymer.
 7. The composition of claim 1, whereinthe first repeat unit of the SAP is selected from the group consistingof

and combinations thereof, wherein each R′ is independently selected fromthe group consisting of *—H, *-Me, *-Et, and *—CF₃, and each n′ is anindependent integer having a value of 1 to
 12. 8. The composition ofclaim 1, wherein the second repeat unit is selected from the groupconsisting of:

and combinations thereof, wherein each R″ is independently selected fromthe group consisting of *—H, *-Me, *-Et.
 9. The composition of claim 1,wherein the polycarbonate block of the block copolymer comprises atrimethylene carbonate repeat unit of structure:


10. The composition of claim 9, wherein the polycarbonate block of theblock copolymer is a homopolymer of the trimethylene carbonate repeatunit.
 11. The composition of claim 1, wherein the polycarbonate block ofthe block copolymer comprises an ester bearing carbonate repeat unitformula (B-3):

wherein R^(g) is a monovalent hydrocarbon group comprising 1-20 carbons.12. The composition of claim 11, wherein R^(g) is selected from thegroup consisting of methyl, ethyl, propyl, and benzyl.
 13. Thecomposition of claim 11, wherein the polycarbonate block of the blockcopolymer is a homopolymer of the ester bearing carbonate repeat unit.14. The composition of claim 1, wherein the first block of the blockcopolymer comprises repeat units of structure:


15. The composition of claim 1, wherein the first block of the blockcopolymer is poly(styrene) (PS) and the second block of the blockcopolymer is poly(trimethylene carbonate) (PTMC).
 16. The composition ofclaim 1, wherein the block copolymer is a triblock copolymer.
 17. Thecomposition of claim 15, wherein the triblock copolymer comprises adivalent central poly(styrene) (PS) block linked at each end to twopoly(trimethylene carbonate) (PTMC) blocks.
 18. The composition of claim1, wherein the composition comprises the SAP in an amount of more than 0wt %, and up to about 10 wt % based on a total dry solids weight of thecomposition.
 19. The composition of claim 1, wherein the compositioncomprises the SAP in an amount of 0.1 wt % to about 5 wt % based ontotal dry solids of the composition.
 20. A method, comprising: providinga first layered structure comprising a top layer (underlayer); disposingthe composition of claim 1 on the underlayer and removing any solvent,thereby forming a second layered structure comprising a film layerdisposed on the underlayer, wherein the film layer comprises the blockcopolymer and the SAP in non-covalent association, and the film layerhas a top surface in contact with an atmosphere; and allowing orinducing the block copolymer of the film layer to self-assemble, therebyforming a third layered structure comprising a phase separated domainpattern having a characteristic pitch Lo, the domain pattern comprisingalternating domains comprising respective chemically distinct blocks ofthe block copolymer; wherein each of the domains has contact with theunderlayer and the atmosphere, and a domain comprising the polycarbonateblock has a higher concentration of the SAP compared to a domaincomprising the first block of the block copolymer.
 21. The method ofclaim 20, comprising selectively etching one of the domains, therebyforming a fourth layered structure comprising an etched domain patterncomprising one or more remaining domains.
 22. The method of claim 20,wherein the underlayer is neutral wetting to the domains of theself-assembled block copolymer.
 23. The method of claim 20, comprisingtransferring the etched domain pattern to the substrate using a wetand/or dry etch process.
 24. The composition of claim 20, wherein thedomain pattern is a lamellar domain pattern, and lamellae of each of thedomains are oriented perpendicular to a main plane of the underlayer.25. The method of claim 20, wherein the domain pattern is a cylindricaldomain pattern comprising cylindrical domains having a central axisoriented perpendicular to a main plane of the underlayer.
 26. The methodof claim 20, wherein the underlayer comprises a poly(styrene-r-methylmethacrylate) random copolymer.
 27. The method of claim 20, wherein theunderlayer comprises a random copolymer comprising: a first repeat ofstructure:

a second repeat unit of structure


28. The method of claim 20, wherein the underlayer comprises a randomcopolymer comprising: a first repeat of structure:

a second repeat unit of structure

wherein a′ has a value greater than or equal to
 1. 29. The method ofclaim 20, comprising baking the film layer at a temperature of about 80°C. to about 220° C. for a period of time, thereby inducing the blockcopolymer to self-assemble.
 30. The method of claim 20, wherein a domaincomprising the first block of the block copolymer has a top surface incontact with the atmosphere and the top surface is essentially free ofthe SAP.
 31. The method of claim 20, wherein the method comprisesforming a topographic resist pattern disposed on the underlayer beforesaid disposing the composition of claim 1, wherein the film layercomprising the block copolymer for self-assembly is substantiallyconfined to recessed regions of the topographic resist pattern.
 32. Amethod, comprising: providing a first layered structure comprising a toplayer (underlayer); forming a topographical resist pattern disposed onthe underlayer, the resist pattern comprising features having recessedregions, the recessed regions having a bottom surface which is a portionof a surface of the underlayer; disposing the composition of claim 1substantially in the recessed regions of the resist pattern and removingany solvent, thereby forming a second layered structure comprising afilm layer, the film layer comprising the block copolymer and the SAP,wherein the film layer is in contact with the bottom surface, the bottomsurface is neutral wetting to the block copolymer, and the film layerhas a top surface in contact with an atmosphere; and allowing orinducing the block copolymer to self-assemble, thereby forming a thirdlayered structure comprising a pattern of phase separated domains(domain pattern) of the block copolymer in the recessed regions, whereineach of the domains is in contact with the bottom surface and theatmosphere, and each of domains is oriented perpendicular to a mainplane of the underlayer.
 33. The method of claim 32, comprisingselectively removing the resist pattern and/or one of the domains,thereby forming a fourth layered structure comprising an etched domainpattern, the etched domain pattern comprising one or more remainingdomains.
 34. The method of claim 32, wherein the resist pattern isformed using a negative tone resist.